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DOI: 10.1002/ejic.201((will be filled in by the editorial staff))

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Exploring the Building Block Potential of Readily Accessible Chiral Zn(salen)
Complexes
Eddy Martin,[a] Marta Martínez Belmonte,[a] Eduardo C. Escudero-Adán,[a] and Arjan W.
Kleij*[a,b]
Keywords: Chiral / Salen ligands / Self-assembly / Synthesis / Zinc
The synthesis and full characterization of a series of chiral Zn(salen)
complexes comprising a 1,2-diphenyl-ethane backbone is reported.
The preparation method here reported simplifies the previously
communicated methodology for these types of Zn complexes that
utilized air-sensitive ZnEt2 (or alike) as metalating reagent. X-ray
molecular structures are also reported for representative examples of
this family of Zn(salen)s.

Introduction
Metallosalens, i.e. complexes derived from salen type ligands
have emerged as privileged catalysts in organic synthesis.[1] More
recently, they have also shown great potential as molecular
synthons[2] in the preparation of various structures including those
incorporating unusual self-assembly behaviour,[3] porous materials
for efficient gas sorption,[4] systems able to mediate chirality transfer
or expression,[5] supramolecular catalysts[6] among others.[7] One of
the building blocks that has been studied intensively over the last ten
years is based on the simple “salphen” motif. The salphen structure
is part of the versatile family of salen ligands having a typical
aromatic bridging group usually being a substituted phenyl. We and
others have studied the reactivity and synthesis of these salphen
systems,[8] in particular when ligated to Zn(II) ions. Notably, these
Zn(salphen)s have been applied as efficient catalyst systems in the
context of CO2 conversion,[9] making using of the high Lewis acidic
nature of the metal ions embedded in the salphen ligand pocket.
Though much is currently known about the potential of
Zn(salphen)s in materials science[2] and homogeneous catalysis,[6, 9]
very little synthetic effort has been devoted to the development of
chiral Zn(salen)s as possible alternatives for Zn(salphen)s in the
aforementioned application areas.[9a,10] The introduction of chirality
in the Zn(salen) complex may hold promise to develop new
materials and catalysts with the advantage that chiral information
could be transduced and new reactivity patterns may become
available. Though the synthesis of Zn-based salphen complexes has
been developed to a sophisticated level, in the case of other salen
based Zn complexes much less synthetic methodology has been
reported (Scheme 1). Of relevant note is the synthesis of salen
complexes having a built-in chiral 1,2-diphenylethane bridge; both
Cozzi[10] and Roesky[11] reported on the use of ZnR2 (R = Me, Et) to

A wide range of functionality is shown to be accessible via the
present route, amplifying the potential use of these (Lewis acidic)
Zn complexes as molecular building blocks. Examples in this
work include the formation of supramolecular assemblies having
built-in bifunctionality using versatile ZnN and ZnO
coordination motifs as guiding tools.

metalate these kind of salen ligands, a procedure that is reminiscent
of the one used by Nguyen and Hupp to obtain similar type of
(supramolecular) Zn(salen)s.[12]

Scheme 1. Comparison between Zn(salphen)s and chiral Zn(salen)s. Note
that only one of the two possible chiral conformations in the Zn(salen)
drawing is shown for simplicity.

Here we report and detail on a more practical type and general
preparation method for a series of Zn(salen)s equipped with a chiral
1,2-diphenylethane bridging fragment. Their building block
potential has also been investigated by proper combination with
suitable (nucleophilic) reagents affording stable, assembled
multinuclear structures, a result that supports that such chiral
Zn(salen)s may also function as supramolecular synthons.

____________

[a]

[b]

Institute of Chemical Research of Catalonia (ICIQ), Av. Països
Catalans 16, 43007 – Tarragona, Spain.
Fax: + 34 – 977 920 828
E-mail: akleij@iciq.es
Catalan Institute for Research and Advanced Studies (ICREA),
Pg. Lluís Companys 23, 08010 – Barcelona, Spain.
Supporting information for this article is available on the WWW
under http://www.eurjic.org/ or from the author.

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Results and Discussion
Synthesis
As a starting point for the synthesis of chiral, 1,2-bis-phenylethane bridged Zn(salen) complexes, we considered the conditions
we employed previously for the Zn(salphen) family of
complexes.[13] Thus, we first tried to combine the diamine reagent
[i.e., (1S,2S)-()-1,2-diphenylethanediamine] and 3,5-di-tert-butylsalicyladehyde in the presence of Zn(OAc)2·2H2O in MeOH to
provide, through a two-step condensation/metalation, the desired
complex 1 (Scheme 2). During the course of the reaction a yellow
precipitate was formed which was, however, identified by 1H NMR
as the non-metalated salen ligand. Apparently, the metalation under
these conditions is comparatively slow and selective isolation of the
ligand precursor to 1 occurs. However, we found that heating this
precursor in its mother liquor dissolves the ligand again, and
addition of NEt3 gave fast precipitation of a product which after
filtration was analysed as the targeted Zn(salen) 1 (78% yield). The
other enantiomer (cf., complex 2 based on (1R,2R)-(+)-1,2diphenylethanediamine) was prepared similarly in 84% isolated
yield. Both these complexes retain MeOH as an axially ligating
ligand (even after prolonged drying) as supported by 1H NMR and
elemental analyses, a result that seems to suggest that the Zn(II)
centres in these systems have a fair degree of Lewis acid character.
Recrystallization of 2 from hot acetonitrile provided crystals suitable
for X-ray analysis (Figure 1).

Figure 1. X-ray molecular structure determined for complex 2·CH3CN. Hatoms, co-crystallized solvent molecules and most of the numbering scheme
are omitted for clarity. Selected bond lengths (Å) and angles (º): Zn(1)-O(1A)
= 1.9719(12), Zn(1)-O(2A) = 1.9589(11), Zn(1)-N(1A) = 2.0985(13), Zn(1)N(2A) = 2.0889(13), Zn(1)-N(1C) = 2.1355(14); N(1A)-Z(1)-N(2A) =
77.60(5), O(1A)-Zn(1)-O(2A) = 96.42(5), N(1A)-Zn(1)-O(2A) = 150.94(5),
N(2A)-Zn(1)-O(1A) = 155.08(5).

The presence of CH3CN (cf., Zn1-N1C bond) in the coordination
sphere of 2 further testifies that these Zn(salen)s 1 and 2 show
similar Lewis acid properties to Zn(salphen)s. The structure reported
here for 2·CH3CN is iso-structural to the one reported by Roesky[11]
where the same complex has an axially ligated Et2O ligand.
The non-substituted Zn(salen) complex 3 could be prepared using
the same methodology, however, the product did not precipitate
during the reaction as was observed in the case of 1 and 2.
Concentration of the reaction mixture did also not lead to
precipitation and therefore another isolation procedure was used.
Addition of water caused precipitation of the product which was
then subsequently filtered and dried to give 3 in 83% isolated yield
which is significantly higher than previously reported (55%).[11] It
should also be noted that no air-sensitive metal reagent (cf., ZnEt2
or ZnMe2) or dry solvents were required making the present method
more attractive from a practical point of view. We then explored the
preparation of a series of Zn(salen)s (Scheme 2, 4-13) with different
functionalities to evaluate further the usefulness of the preparative
method. In general high isolated yields could be obtained (up to
92%) except for complexes 11 (44%) and 13 (56%) whose isolation
proved to be more challenging. Of particular note are the syntheses
of Zn(salen) complexes 6, 8, 11 and 13 incorporating potentially
useful allyl, protected alkyne and pyridyl groups. Such
functionalities have already proven to be highly useful in the
construction of multimetallic Zn(salen) assemblies via olefin
metathesis chemistry[14] or ZnNpyr coordination patterns.[13a,15]
Whereas in the majority of the cases the product simply precipitates
out during the course of the reaction, the isolation of complexes 5
and 11 required significant concentration of the reaction mixture and
extensive sonication periods and/or addition of pyridine (see
Experimental Section). Complex 5 was isolated as its pyridine
adduct in line with the observed Lewis acid behaviour observed for
Zn(salen)s 1 and 2.

Scheme 2. Synthesis of chiral Zn(salen) complexes 1-13; for each complex
the absolute configuration is also indicated together with the isolated yield.

The synthesis of complex 13 requires a more detailed explanation.
We first attempted to prepare 13 using the standard procedure used
for the other complexes (see Experimental Section). Shortly after
addition of the Zn reagent, a yellow solid precipitated out and after
isolation the 1H NMR spectrum recorded in

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Figure 2. Part of the X-ray molecular structure determined for the polymeric side-product during the synthesis of 13. H-atoms are omitted are omitted for
clarity. Selected bond lengths (Å) and angles (º) around one of the metal ions: Zn(1)-O(1) = 2.0416(13), Zn(1)-O(1C) = 2.0416(13), Zn(1)-O(2) = 2.1024(14),
Zn(1)-O(2C) = 2.1024(14), Zn(1)-N(1A) = 2.1595(15), Zn(1)-N(1D) = 2.1595(15); N(1A)-Zn(1)-N(1D) = 180.0, O(1)-Zn(1)-O(1C) = 180.0, O(2)-Zn(1)O(2C) = 180.00(8), O(1)-Zn(1)-O(2) = 88.45(5), O(1C)-Zn(1)-O(2C) = 88.45(5), O(1)-Zn(1)-N(1A) = 89.62(6), O(1)-Zn(1)-N(1D) = 90.38(6).

[D6]DMSO clearly displayed a mixture of two principal components.
Recrystallization of the crude product from DMSO afforded
fortunately, crystals suitable for X-ray analysis providing crucial
information about the identity of non-desired component in the
isolated mixture (see Figure 2). The structure shows the presence of
the 3tert-butyl-5-(4-pyridyl)-salicylaldehyde reagent forming a
polymeric, porous structure combined with ZnII ions. Each Zn centre
is ligated by two anionic salicylaldehyde fragments and the
octahedral coordination geometry around the ion is completed by
two pyridine donors originating from distinct salicylaldehyde
groups. Unusual triangular shaped pores are formed from three Zn
centres and three salicylaldehyde units. This feature shows
periodicity in the solid state to afford a polymer with porous
channels along one of the crystallographic axes (see the Supporting
Information for details).
Realizing that the formation of this stable metal-organic
framework efficiently competes with the formation of targeted
Zn(salen) complex 13, we then performed the reaction in the
presence of pyridine as co-solvent to prevent early precipitation of
the aforementioned side-product and this proved to be helpful;
complex 13 could be isolated in fair yield (56%) and purity. All
complexes were fully characterized by 1H/13C1H NMR (for 7 also
by 19F1H NMR), MALDI-TOF mass spectrometry and elemental
analyses. Complex 10 was also characterized by single crystal X-ray
crystallography (Figure 3).

Figure 3. X-ray molecular structure determined for complex 10·DMSO. Hatoms, co-crystallized solvent molecules and most of the numbering scheme
are omitted for clarity. Only one of the crystallographically independent
molecules is shown. Selected bond lengths (Å) and angles (º): Zn(1A)-O(1A)
= 1.989(3), Zn(1A)-O(2A) = 1.983(3), Zn(1A)-N(1A) = 2.079(3), Zn(1A)N(2A) = 2.077(3), Zn(1A)-O(7A) = 2.039(3); O(2A)-Zn(1A)-O(1A) =
93.29(12), N(2A)-Zn(1A)-N(1A) = 79.46(12), O(2A)-Zn(1A)-N(1A) =
146.00(11), N(2A)-Zn(1A)-O(1A) = 166.39(11), O(2A)-Zn(1A)-O(7A) =
107.18(11), N(2A)-Zn(1A)-O(7A) = 93.48(11).

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Assembly formation with chiral Zn(salen)s
The chiral Zn(salen)s were probed for their ability to form larger
multinuclear assemblies. As a role model, Zn(salphen)s have
previously demonstrated to readily form such ensembles using a
variety of ditopic ligands including DABCO (= 1,4diazabicyclo[2.2.2]octane),[16] bipyridines,[13a] carboxylates[5c,17]
and hydroxo ligands.[18] Thus, such ligands may serve as good
probes to determine the building block potential of the chiral
Zn(salen) complexes reported in this work. Previous work on chiral
Zn(salen)s has shown potential in this respect by evaluation of their
binding affinity with pyridine;[19] Zn(salen)s with chiral 1,2diphenylethane bridging fragment show stability constants Ks in the
range 104105 M-1, just slightly lower than reported for their
Zn(salphen) analogues.[13a] We thus first investigated the use of a
ditopic ligand (dabco) to enforce the formation of a 2:1 assembly
where both dabco-N atoms would be involved in binding to the Zn
ions. This assembly (14) was easily prepared by combination of
Zn(salen) complex 1 with dabco in hot acetonitrile. Cooling of the
solution resulted in the formation of needle-shaped crystals which
were isolated by filtration (46%) and analysed by 1H NMR (both
[D6]acetone as well as [D2]DCM were used). In both
aforementioned solvents, by comparison with “free” dabco, a
relatively small upfield displacement is noted for the dabco
hydrogens ( = 0.06 and 0.11 ppm, respectively). Both species
integrate such that a 2:1 ratio is supported in the isolated crystalline
solid. In both solvents, one singlet peak for the dabco-H is noted and
only one pattern for the Zn(salen) complex in line with fast exchange
between 1:1 and 2:1 assemblies and/or a low energetic barrier for
rotation around the ZnNdabco bonds. As a definite proof of the 2:1
stoichiometry X-ray analysis of crystalline 14 (from CH3CN) was
carried out (Figure 4); in the solid-state arrangement both Zn(salen)
units are in a parallel arrangement and it may be assumed that there
is ample room for free rotation around both ZnNdabco axes in
solution.

(15) could be obtained as single crystalline material from a saturated
solution in acetone. The structure that was determined (see Figure 5)
shows the presence of two units of Zn(salen) 2 connected through
an OH anion (NBu4 cation not shown here). Since the two Zn(salen)
fragments are bridged by one of the smallest ligands possible,
anisotropic effects may be expected if the structure is retained in
solution. Therefore, in order to evaluate the stability of assembly 15
in solution analysis by 1H NMR ([D6]acetone) was carried out and
its NMR spectrum compared to the one from free, non-assembled
Zn(salen) 2. Significant changes were noted between the assembly
15 (containing two, OHbridged Zn(salen) complexes 2) and free
Zn(salen) 2 (Figure 6).

Figure 5. X-ray molecular structure (POV-Ray image) determined for
assembly 15. H-atoms, co-crystallized solvent molecules are omitted for
clarity. Colour coding: Zn = Green, O = red, N = blue, C = grey.

Figure 4. X-ray molecular structure (POV-Ray image) determined for
assembly 14. H-atoms, co-crystallized solvent molecules are omitted for
clarity. Colour coding: Zn = Green, O = red, N = blue, C = grey.

Next, we examined a potentially ditopic ligand with a much
smaller interconnecting spanning range, i.e. a hydroxide. To this end,
complex 2 was combined with NBu4OH in CH3CN. After isolation
(see Experimental Section) the envisioned assembly (2)2·NBu4OH

For each of the salen units in assembly 15 a dissymmetry is apparent
as supported by the presence of multiple signals for the arylhydrogens, the imine-H and the bridging Ph(H)CC(H)Ph unit. The
latter split up and give rise to an ABpattern with a typical 2J of
around 11 Hz. These doublets also show a hyperfine coupling with
both the imine-H (4J = 1.21.4 Hz) located at 7.80 and 7.39 ppm,
respectively. The position of these two imine-H is significantly
different from the one observed for free, unbound 2 ( = 8.18 ppm)
suggesting the close mutual presence of both salen units. This causes
a shielding effect of the aromatic groups exerted by their -electron
ring currents, and displaces all nearby groups to higher field as is
indeed observed for the imine-H, the CHCH fragment, aromatic
protons and to a lesser extend the tBu groups. These data are in line
with a stable character of the assembly 15 under these conditions. It
should be noted that the 1H NMR spectrum of 15 also shows
indications of a 1:1 assembly (i.e., 2·NBu4OH, see Supporting
Information); when a competitive ligand is added in small amount
(i.e., [D6]DMSO), the amount of the 1:1 assembly increases and thus
shows that binding of 2 to the OH donor ligand is reversible.

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Hb

Hd,Hc

Ha,Hb

Hf,H

Ha

He,g
Hc,Hd

Figure 6. Selected 1H NMR region ([D6]acetone) for Zn(salen) complex 2 (top) and assembly 15 (NBu4 cation not shown for clarity).

Mass spectrometric analysis carried out for 15 indirectly
supported the stability of the assembled species; since MeOH was
used for the electrospray ionization mass analyses, the OH anion was
easily replaced by a methoxy anion through acid-base chemistry and
both the 1:1 as well as the 2:1 assembly having a MeO anion
associated were observed. Together with these characteristic anionic
assemblies also those based on EtO, PrO and even BuO were
generated in situ as a likely result of the MeOH containing higher
alcohol impurities. This result nonetheless demonstrates that such
anionic assemblies are sufficiently stable to be formed and analysed
by soft MS methods.

Conclusions
In this work we have presented a more facile, general route
towards chiral Zn(salen)s based on a 1,2-diphenyl-ethanediamine
bridging unit. This method uses simple precursors and can be
applied in air and moisture-containing solvent producing the desired
Zn(salen)s in fair to high isolated yields. This method tolerates the
introduction of synthetically useful acetylenic, allylic and pyridine
groups that can be used for post-modification or direct self-assembly
(in the case of 13). The potential of these chiral Zn(salen)s has been
demonstrated by the easy formation of two types of assemblies
based on either dabco or NBu4OH donors. Thus, these chiral
Zn(salen)s may hold promise as steric spectators (after complexation
to suitable O or Ndonors of the host) in supramolecular catalyst
design providing a chiral environment around the reactive centre[20]
and leading to possible asymmetric induction.

Experimental Section

General: NMR measurements were done on a Bruker AV-400 or AV-500
spectrometer and referenced to the residual deuterated solvent signals.
Elemental analysis was performed by the Unidád de Análisis Elemental at
the Universidad de Santiago de Compostela. Mass spectrometric analysis and
X-ray diffraction studies were performed by the Research Support Group at
the ICIQ. The chiral diamine precursors A and B (Scheme 2) were
commercially purchased, the salicylaldehyde precursors used for the
synthesis of complexes 8[21] and 13[22] were prepared according to previously
reported procedures while the others were purchased from commercial
suppliers. Copies of NMR spectra of all isolated Zn(salen) complexes 1-13
are provided in the Supporting Information.
Zn(salen)
complex
(1):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (172.8 mg, 0.814 mmol), 3,5-di-tert-butylsalicylaldehyde (426.6 mg, 1.82 mmol) and Zn(OAc)2·2H2O (322.2 mg, 1.47
mmol) in MeOH (40 ml) and NEt3 (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 18 h. The
desired compound was then isolated by filtration and dried in vacuo to yield
a yellow solid. Yield: 469.5 mg (0.634 mmol, 78%; yield of monoMeOH
solvate). 1H NMR (400 MHz, [D6]DMSO): δ = 8.18 (s, 2H; CH=N), 7.327.39 (m, 8H; ArH), 7.24-7.29 (m, 2H; ArH), 7.21 (d, 4JH,H = 2.6 Hz, 2H; ArH),
6.75 (d, 4JH,H = 2.6 Hz, 2H; ArH), 5.03 (s, 2H, CHCH), 4.11 (q, 3JHH = 5.3
Hz, 1H; CH3OH), 3.18 (d, 3JHH = 5.2 Hz, 3H; CH3OH), 1.47 (s, 18H;
C(CH3)3), 1.19 (s, 18H; C(CH3)3); 13C{1H} NMR (100 MHz, [D6]DMSO): δ
= 170.01, 169.69, 141.93, 140.88, 132.86, 129.00, 128.88, 128.60, 127.97,
127.64, 118.34, 72.47, 49.07, 35.66, 33.84, 31.86, 30.06; MS (MALDI+,
pyrene): m/z = 706.2 [M]+ (calcd 706.3), 694.1 (M – CH3 + 2H)+ (calcd
694.3); elemental analysis calcd for C44H54N2O2Zn·MeOH·2½H2O: C 68.82,
H 8.09, N, 3.57; found: C 69.02, H 7.68, N 3.33. The presence of 1 equiv of
MeOH was supported by 1H NMR analysis, see the Supporting Information.

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This MeOH could not be removed by heating the compound for longer
periods of time.
Zn(salen)
complex
(2):
A
solution
of
(1R,2R)-()-1,2diphenylethylenediamine (169.4 mg, 0.798 mmol), 3,5-di-tert-butylsalicylaldehyde (488.0 mg, 2.08 mmol) and Zn(OAc)2·2H2O (308.9 mg, 1.40
mmol) in MeOH (35 ml) and NEt3 (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 18 h. The
desired compound was then isolated by filtration and dried in vacuo to yield
a yellow solid. Yield: 497.9 mg (0.673 mmol, 84%; yield of monoMeOH
solvate). 1H NMR (400 MHz, [D6]DMSO): δ = 8.18 (s, 2H; CH=N), 7.337.39 (m, 8H; ArH), 7.25-7.29 (m, 2H; ArH), 7.21 (d, 4JH,H = 2.6 Hz, 2H; ArH),
6.75 (d, 4JH,H = 2.6 Hz, 2H; ArH), 5.03 (s, 2H, CHCH), 4.10 (q, 3JHH = 5.3
Hz, 1H; CH3OH), 3.17 (d, 3JHH = 5.3 Hz, 3H; CH3OH), 1.47 (s, 18H;
C(CH3)3), 1.19 (s, 18H; C(CH3)3); 13C{1H} NMR (100 MHz, [D6]DMSO): δ
= 170.00, 169.69, 141.93, 140.88, 132.84, 128.99, 128.88, 128.57, 127.96,
127.63, 118.34, 72.46, 49.07, 35.66, 33.84, 31.85, 30.05; MS (MALDI+,
pyrene): m/z = 706.3 [M]+ (calcd 706.3), 694.3 (M – CH3 + 2H)+ (calcd
694.3); elemental analysis calcd for C44H54N2O2Zn·MeOH: C 73.01, H 7.90,
N, 3.78; found: C 73.11, H 7.48, N 3.73. As for complex 1, the presence of
1 equiv of MeOH was supported by 1H NMR analysis, see the Supporting
Information. This MeOH could not be removed by heating the compound for
longer periods of time.
Zn(salen)
complex
(3):
A
solution
of
(1R,2R)-()-1,2diphenylethylenediamine (136.7 mg, 0.644 mmol), salicylaldehyde (213.4
mg, 1.75 mmol) and Zn(OAc)2·2H2O (223.6 mg, 1.02 mmol) in MeOH (30
ml) and NEt3 (1 mL) was shortly stirred at reflux temperature and then
allowed to cool to r.t. and stirred for another 22 h. At this stage the yellow
solution was concentrated to around 20 mL and water was added to initiate
precipitation of the product. The product (a white solid) was then collected
by filtration and dried. Yield: 259.9 mg (0.537 mmol, 83%). 1H NMR (400
MHz, [D6]DMSO): δ = 8.22 (s, 2H; CH=N), 7.40 (d, 3JH,H = 7.9 Hz, 4H; ArH),
7.34 (t, 3JH,H = 7.5 Hz, 4H; ArH), 7.26 (t, 3JH,H = 6.9 Hz, 2H; ArH), 7.15 (t,
3
JH,H = 7.7 Hz, 4JH,H = 1.7 Hz, 2H; ArH), 7.00 (d, 3JH,H = 7.8 Hz, 4JH,H = 1.8
Hz, 2H; ArH), 6.65 (d, 3JH,H = 8.0 Hz, 2H; ArH), 6.38 (t, 3JH,H = 7.3 Hz, 4JH,H
= 1.0 Hz, 2H; ArH), 5.10 (s, 2H, CHCH); 13C{1H} NMR (100 MHz,
[D6]DMSO): δ = 171.80, 170.18, 141.52, 135.58, 133.85, 128.96, 128.22,
127.97, 123.23, 119.70, 112.81, 72.82; MS (MALDI+, dctb): m/z = 482.3
[M]+ (calcd 482.1), 968.4 (2M)+ (calcd 968.2); elemental analysis calcd for
C28H22N2O2Zn·1.33H2O: C 66.22, H 4.90, N, 5.52; found: C 66.50, H 5.04,
N 5.56.

Zn(salen)
complex
(4):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (141.0 mg, 0.664 mmol), 3-methylsalicylaldehyde (241.1 mg, 1.77 mmol) and Zn(OAc)2·2H2O (247.0 mg, 1.13
mmol) in MeOH (25 ml) and NEt3 (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 5 h. The
product (a yellow solid) was then collected by filtration and dried. Yield:
276.9 mg (0.541 mmol, 81%). 1H NMR (400 MHz, [D6]DMSO): δ = 8.16 (s,
2H; CH=N), 7.45 (d, 3JH,H = 7.1 Hz, 4JH,H = 1.5 Hz, 4H; ArH), 7.34 (t, 3JH,H
= 7.6 Hz, 4JH,H = 0.9 Hz, 4H; ArH), 7.26 (t, 3JH,H = 7.3 Hz, 4JH,H = 2.4 Hz, 2H;
ArH), 7.12 (t, 3JH,H = 6.9 Hz, 4JH,H = 0.9 Hz, 2H; ArH), 6.83 (d, 3JH,H = 7.8
Hz, 4JH,H = 1.8 Hz, 2H; ArH), 6.30 (dd, 3JH,H = 7.4 Hz, 2H; ArH), 5.06 (s, 2H,
CHCH), 2.26 (Ar-CH3); 13C{1H} NMR (100 MHz, [D6]DMSO): δ = 170.40,
170.38, 141.96, 133.72, 133.37, 130.42, 128.92, 128.11, 127.88, 118.53,
112.25, 73.41, 17.65; MS (MALDI+, pyrene): m/z = 510.1 [M]+ (calcd
510.1); elemental analysis calcd for C30H26N2O2Zn·1/3H2O: C 69.57, H 5.19,
N 5.41; found: C 69.81, H 4.90, N 5.40.

Zn(salen)
complex
(5):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (210.3 mg, 0.991 mmol), 3-tert-butylsalicylaldehyde (415.9 mg, 2.33 mmol) and Zn(OAc)2·2H2O (337.8 mg, 1.54
mmol) in MeOH (30 ml) and pyridine (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 18 h. The
product (a yellow solid) was then collected by filtration and dried. Yield:
511.4 mg (0.757 mmol, 76%; isolated as monopyridine adduct). 1H NMR
(400 MHz, [D6]Acetone): δ = 8.27-8.29 (m, 2H; Pyr-H), 8.25 (s, 2H; CH=N),
7.86 (t, 3JH,H = 7.7 Hz, 4JH,H = 1.8 Hz, 1H; Pyr-H), 7.36-7.38 (m, 2H; Pyr-H),
7.34 (d, 3JH,H = 7.1 Hz, 4JH,H = 1.5 Hz, 4H; ArH), 7.34 (t, 3JH,H = 6.8 Hz, 4H;
ArH), 7.18-7.26 (m, 8H; ArH), 6.86 (d, 3JH,H = 7.8 Hz, 4JH,H = 1.8 Hz, 2H;
ArH), 6.35 (t, 3JH,H = 7.6 Hz, 2H; ArH), 5.15 (s, 2H, CHCH), 1.45
(C(CH3)3); 13C{1H} NMR (100 MHz, [D6]Acetone): δ = 171.99, 170.11,
148.33, 141.78, 140.60, 138.72, 133.53, 129.73, 128.45, 128.26, 127.54,
124.66, 119.45, 111.65, 72.62, 35.04, 29.12; MS (MALDI+, pyrene): m/z =
594.1 [M]+ (calcd 594.2); elemental analysis calcd for C41H43N3O2Zn (monopyridine complex): C 72.93, H 6.42, N 6.22; found: C 72.70, H 6.14, N 6.13.
Zn(salen)
complex
(6):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (164.1 mg, 0.773 mmol), 3-methoxy-5-allylsalicylaldehyde (359.2 mg, 1.87 mmol) and Zn(OAc)2·2H2O (313.8 mg, 1.43
mmol) in MeOH (30 ml) and NEt3 (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 16 h. The
product (a yellow solid) was then collected by filtration and dried. Yield:
370.8 mg (0.594 mmol, 77%). 1H NMR (500 MHz, [D6]DMSO): δ = 8.18 (s,
2H; CH=N), 7.39 (d, 3JH,H = 7.5 Hz, 4H; ArH), 7.33 (t, 3JH,H = 7.8 Hz, 4H;
ArH), 7.25 (t, 3JH,H = 7.3 Hz, 2H; ArH), 6.34 (d, 4JH,H = 1.9 Hz, 2H; ArH),
6.40 (d, 4JH,H = 1.4 Hz, 2H; ArH), 5.86-5.94 (m, 2H, allyl), 5.08 (s, 2H,
CHCH), 5.04 (d, 2JH,H = 17.0 Hz, 4JH,H = 1.6 Hz, 2H; allyl), 4.98 (d, 2JH,H =
10.0 Hz, 2H; ArH), 3.73 (s, 6H; ArOMe), 3.17 (d, 3JH,H = 6.7 Hz, 4H; allyl);
13
C{1H} NMR (126 MHz, [D6]DMSO): δ = 170.03, 161.47, 152.77, 141.65,
138.84, 128.92, 128.19, 127.90, 125.35, 122.34, 118.07, 115.53, 114.64,
72.87, 55.58, 39.39; MS (MALDI+, pyrene): m/z = 622.1 [M]+ (calcd 622.2);
elemental analysis calcd for C36H34N2O2Zn·1.5H2O: C 66.41, H 5.73, N 4.30;
found: C 66.52, H 5.35, N 4.23.
Zn(salen)
complex
(7):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (136.6 mg, 0.643 mmol), 3,5-difluorosalicylaldehyde (298.6 mg, 1.89 mmol) and Zn(OAc)2·2H2O (340.1 mg, 1.55
mmol) in MeOH (35 ml) and NEt3 (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 45 min.
The product (a yellow solid) was then collected by filtration and dried. Yield:
303.2 mg (0.545 mmol, 85%). 1H NMR (500 MHz, [D6]DMSO): δ = 8.31 (s,
2H; CH=N), 7.41 (d, 3JH,H = 8.0 Hz, 4H; ArH), 7.36 (t, 3JH,H = 7.9 Hz, 4H;
ArH), 7.28 (t, 3JH,H = 7.2 Hz, 2H; ArH), 7.17-7.27 (m, 2H; ArH), 6.80-6.82
(m, 2H; ArH), 5.19 (s, 2H, CHCH); 19F1H NMR (376 MHz, [D6]DMSO):
δ = 130.45, 131.43; 13C{1H} NMR (126 MHz, [D6]DMSO): δ = 169.66,
157.17, 155.73, 153.79, 149.85, 148.02, 140.86, 129.07, 128.10, 119.02,
113.76, 108.20, 73.02; MS (MALDI+, pyrene): m/z = 554.1 [M]+ (calcd
554.1), 1110.1 (2M)+ (calcd 1110.1); elemental analysis calcd for
C28H18F4N2O2Zn·H2O: C 58.60, H 3.51, N 4.88; found: C 58.40, H 3.36, N
4.88.
Zn(salen)
complex
(8):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (133.6 mg, 0.629 mmol), 5-trimethylsilylacetylylsalicylaldehyde[21] (341.5 mg, 1.56 mmol) and Zn(OAc)2·2H2O (436.3 mg,
1.98 mmol) in MeOH (30 ml) and NEt3 (1 mL) was shortly stirred at reflux
temperature and then allowed to cool to r.t. and stirred for another 18 h. The
product (a light yellow/brown solid) was then collected by filtration and dried.
Yield: 390.4 mg (0.577 mmol, 92%). 1H NMR (500 MHz, [D6]DMSO): δ =
8.21 (s, 2H; CH=N), 7.33-7.36 (m, 8H; ArH), 7.26-7.31 (m, 2H; ArH), 7.20-

7

FULL PAPER
7.24 (m, 4H; ArH), 6.62 (d, 3JH,H = 8.8 Hz, 2H; ArH), 5.12 (s, 2H, CHCH),
0.17 (s, 18H; SiMe3); 13C{1H} NMR (100 MHz, [D6]DMSO): δ = 172.14,
169.61, 140.55, 139.97, 136.52, 129.04, 128.37, 128.16, 123.80, 119.65,
106.99, 106.11, 90.73, 72.57, 0.65; MS (MALDI+, pyrene): m/z = 674.2 [M]+
(calcd 674.2); elemental analysis calcd for C38H38Si2N2O2Zn·2H2O: C 64.07,
H 5.94, N 3.93; found: C 63.72, H 5.49, N 3.79.
Zn(salen)
complex
(9):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (160.8 mg, 0.757 mmol), 3,5-dichlorosalicylaldehyde (365.3 mg, 1.91 mmol) and Zn(OAc)2·2H2O (256.1 mg, 1.17
mmol) in MeOH (40 ml) was stirred at r.t. for 20 min. The product (a yellow
solid) was then collected by filtration and dried. Yield: 406.7 mg (0.654
mmol, 96%). 1H NMR (400 MHz, [D6]DMSO): δ = 8.33 (s, 2H; CH=N), 7.48
(d, 4JH,H = 2.9 Hz, 2H; ArH), 7.40 (d, 3JH,H = 7.9 Hz, 4H; ArH), 7.35 (t, 3JH,H
= 7.5 Hz, 4H; ArH), 7.28 (t, 3JH,H = 7.2 Hz, 2H; ArH), 7.18 (d, 4JH,H = 2.8 Hz,
2H; ArH), 5.16 (s, 2H, CHCH); 13C{1H} NMR (100 MHz, [D6]DMSO): δ
= 169.88, 164.43, 140.81, 133.10, 132.54, 129.07, 128.17, 127.97, 127.06,
120.66, 115.11, 73.28; MS (MALDI+, pyrene): m/z = 620.0 [M]+ (calcd
619.9), ; elemental analysis calcd for C28H18Cl4N2O2Zn·H2O: C 52.57, H 3.15,
N, 4.38; found: C 52.48, H 2.96, N 4.30.
Zn(salen)
complex
(10):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (101.2 mg, 0.477 mmol), 5-nitro-salicylaldehyde
(187.9 mg, 1.12 mmol) and Zn(OAc)2·2H2O (270.6 mg, 1.17 mmol) in
MeOH (40 ml) was stirred at r.t. for 60 min. The product (a yellow solid)
was then collected by filtration and dried. Yield: 248.2 mg (0.433 mmol,
91%). 1H NMR (400 MHz, [D6]DMSO): δ = 8.45 (s, 2H; CH=N), 8.20 (d,
4
JH,H = 3.1 Hz, 2H; ArH), 8.04 (d, 3JH,H = 9.5 Hz, 4JH,H = 3.1 Hz, 2H; ArH),
7.36-7.38 (m, 8H; ArH), 7.27-7.33 (m, 2H; ArH), 6.76 (d, 3JH,H = 9.5 Hz, 2H;
ArH), 5.24 (s, 2H, CHCH), 4.10 (q, 3JHH = 5.2 Hz, 1H; CH3OH), 3.18 (d,
3
JHH = 5.3 Hz, 3H; CH3OH); 13C{1H} NMR (100 MHz, [D6]DMSO): δ =
176.76, 169.90, 139.92, 134.41, 133.66, 129.18, 128.76, 128.43, 128.37,
123.89, 118.53, 72.38, 49.07; MS (MALDI, DCTB): m/z = 572 [M] (calcd
572), 822 (M+DCTB) (calcd 822), 1118 ( with dctb being trans-2-[3-(4tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile, Mw = 250.34;
elemental analysis calcd for C28H20N4O6Zn·½MeOH·3H2O: C 55.49, H 4.08,
N 9.08; found: C 55.07, H 3.97, N 8.78. As for complex 1, the presence of
0.5 equiv of MeOH was supported by 1H NMR analysis, see the Supporting
Information. This MeOH could not be removed by heating the compound for
longer periods of time.
Zn(salen)
complex
(11):
A
solution
of
(1S,2S)-()-1,2diphenylethylenediamine (171.1 mg, 0.806 mmol), 3-allyl-salicylaldehyde
(329.3 mg, 2.03 mmol) and Zn(OAc)2·2H2O (395.0 mg, 1.80 mmol) in
MeOH (25 ml) and NEt3 (1 mL) was stirred at r.t. for 18 h. Then the solution
was concentrated to 10 mL and sonicated briefly. In due course, a yellow
solid started to preciptate and the product collected by filtration and dried.
Yield: 200.2 mg (0.355 mmol, 44%). 1H NMR (400 MHz, [D6]DMSO): δ =
8.16 (s, 2H; CH=N), 7.40 (d, 3JH,H = 7.8 Hz, 4H; ArH), 7.34 (t, 3JH,H = 7.7 Hz,
4H; ArH), 7.26 (t, 3JH,H = 7.1 Hz, 4JH,H = 1.4 Hz, 2H; ArH), 7.06 (d, 3JH,H =
7.0 Hz, 4JH,H = 1.7 Hz, 2H; ArH), 6.87 (d, 3JH,H = 7.8 Hz, 4JH,H = 1.8 Hz, 2H;
ArH), 6.33 (t, 3JH,H = 7.4 Hz, 2H; ArH), 6.08-6.16 (m, 2H; allyl-H), 5.13 (d,
2
JH,H = 17.3 Hz, 4JH,H = 1.4 Hz, 2H; allyl-H), 5.07 (s, 2H, CHCH), 5.00 (d,
2
JH,H = 10.0 Hz, 4JH,H = 1.2 Hz, 2H; allyl-H), 3.40 (dd, 3JH,H = 5.4 Hz, 4H;
allyl-H); 13C{1H} NMR (100 MHz, [D6]DMSO): δ = 169.96, 169.66, 141.45,
138.74, 133.73, 132.82, 132.61, 128.97, 128.42, 128.00, 118.88, 115.29,
112.32, 72.87, 35.10; MS (MALDI+, pyrene): m/z = 563.1 [M+H]+ (calcd
563.2); elemental analysis calcd for C34H30N2O2Zn·½H2O: C 71.27, H 5.45,
N 4.89; found: C 71.63, H 5.73, N 4.99.

Zn(salen)
complex
(12):
A
solution
of
(1R,2R)-()-1,2diphenylethylenediamine (162.6 mg, 0.766 mmol), 5-methylsalicylaldehyde (236.3 mg, 1.74 mmol) and Zn(OAc)2·2H2O (225.8 mg, 1.03
mmol) in MeOH (35 ml) and NEt3 (1 mL) was stirred at r.t. for 2 days. Then
the product (a yellow solid) was collected by filtration and dried. Yield: 313.3
mg (0.612 mmol, 80%). 1H NMR (400 MHz, [D6]DMSO): δ = 8.12 (s, 2H;
CH=N), 7.38 (d, 3JH,H = 7.8 Hz, 4H; ArH), 7.33 (t, 3JH,H = 7.7 Hz, 4H; ArH),
7.26 (t, 3JH,H = 7.2 Hz, 4JH,H = 1.3 Hz, 2H; ArH), 6.98 (d, 3JH,H = 8.6 Hz, 4JH,H
= 2.4 Hz, 2H; ArH), 6.76 (d, 4JH,H = 2.1 Hz, 2H; ArH), 6.58 (d, 3JH,H = 8.6 Hz,
2H; ArH), 5.07 (s, 2H, CHCH), 2.09 (s, 6H, ArMe); 13C{1H} NMR (100
MHz, [D6]DMSO): δ = 169.91, 169.74, 141.28, 135.18, 134.84, 128.95,
128.39, 127.97, 123.10, 120.68, 118.93, 72.72, 20.14; MS (MALDI+, dctb):
m/z = 510.3 [M]+ (calcd 510.1), 1025.3 (2M+H)+ (calcd. 1025.3); elemental
analysis calcd for C30H26N2O2Zn·½H2O: C 69.17, H 5.22, N 5.38; found: C
69.47, H 5.27, N 5.41.
Zn(salen)
complex
(13):
A
solution
of
(1R,2R)-()-1,2diphenylethylenediamine (66.0 mg, 0.311 mmol), 3-tert-butyl-5-(4-pyridyl)salicylaldehyde[22] (166.9 mg, 0.654 mmol) and Zn(OAc)2·2H2O (81.0 mg,
0.369 mmol) in MeOH (20 ml) and pyridine (0.5 mL) was stirred at r.t. for
65 h and then filtered to give the product as a yellow solid. Yield: 129.5 mg
(0.0173 mmol, 56%). 1H NMR (400 MHz, [D6]DMSO): δ = 8.39-8.41 (m,
4H; pyr-H), 8.29 (s, 2H; CH=N), 7.56-7.58 (m, 4H; pyr-H), 7.4 (d, 4JH,H =
2.4 Hz, 2H; ArH), 7.31-7.37 (m, 8H; ArH), 7.24-7.28 (m, 2H; ArH), 5.16 (s,
2H, CHCH), 1.51 (s, 18H, C(CH3)3); 13C{1H} NMR (100 MHz,
[D6]DMSO): δ = 172.86, 170.61, 148.02, 140.64, 132.80, 128.95, 128.45,
128.10, 128.07, 124.08, 119.91, 119.87, 72.21, 35.67, 29.70; MS (MALDI+,
pyrene): m/z = 749.4 [M+H]+ (calcd 749.3); elemental analysis calcd for
C30H26N2O2Zn·2½H2O: C 69.47, H 6.21, N 7.04; found: C 69.38, H 5.82, N
6.99.
Assembly (1)2·dabco (14): A hot solution of Zn(salen) complex 1 (110.5 mg,
0.149 mmol) in CH3CN (25 mL) was added to dabco (9.8 mg, 0.0874 mmol)
and the mixture was shortly heated to reflux and then allowed to cool to r.t.
In due course the product crystallized out as yellow needles which were
collected by filtration and dried. Yield: 64.7 mg (0.0406 mmol, 46%). 1H
NMR (400 MHz, [D6]Acetone): δ = 8.02 (s, 4H; CH=N), 7.21-7.37 (m, 24H;
ArH), 6.67 (d, 4JH,H = 2.7 Hz, 4H; ArH), 5.15 (s, 4H, CHCH), 2.96 (s, 12H;
dabco-H), 1.50 (s, 36H; C(CH3)3), 1.22 (s, 36H; C(CH3)3); 13C{1H} NMR
(100 MHz, [D6] Acetone): δ = 169.84, 169.68, 140.91, 138.80, 132.89,
129.59, 129.00, 128.58, 128.23, 128.21, 128.01, 127.90, 118.12, 72.15, 46.41,
35.30, 33.34, 30.91 (one C-signal is overlapping with solvent residual peaks);
MS (ESI+, MeOH): m/z = 707.3 (1+H)+ (calcd. 707.4), 729.3 (1+Na)+ (calcd.
729.3), 819.4 (1·dabco+H)+ (calcd. 819.5), 1417.6 (2M+H)+ (calcd. 1417.7),
1439.6 (2M+Na)+ (calcd. 1439.7): elemental analysis calcd for
C94H120N6O4Zn2·2H2O: C 72.15, H 7.99, N 5.37; found: C 72.31, H 7.96, N
5.50.
Assembly (1)2/NBu4OH (15): A solution of (1R,2R)-configured Zn(salen)
complex 2 (286.9 mg, 0.405 mmol) in CH3CN (10 mL) was added NBu4OH
(0.5 mL of a 1 M solution in MeOH). Soon after the addition of the later the
mixture was concentrated to about 3 mL and cooled to 30ºC. A few drops
of water were added to induce precipitation of the product (light
orange/yellow solid), which was collected by filtration and dried. Yield:
203.3 mg (0.210 mmol, 52%). Crystals were obtained from a saturated
solution in [D6]acetone. 1H NMR (400 MHz, [D6]Acetone): δ = 7.80 (d, 4JH,H
= 1.4 Hz, 2H; CH=N), 7.39 (d, 4JH,H = 1.8 Hz, 2H; CH=N), 7.24 (d, 4JH,H =
2.6 Hz, 2H; ArH), 7.20 (d, 4JH,H = 2.6 Hz, 2H; ArH), 6.99-7.11 (m, 16H; ArH),
6.79 (m, 4H; ArH), 6.50 (d, 4JH,H = 2.6 Hz, 2H; ArH), 6.44 (d, 4JH,H = 2.6 Hz,
2H; ArH), 4.85 (d, 2JH,H = 11.0 Hz, 4JH,H = 1.2 Hz, 2H; CHACHB), 4.69 (d,
2
JH,H = 11.3 Hz, 4JH,H = 1.4 Hz, 2H; CHACHB), 3.44-3.48 (m, 8H; NCH2),

8

FULL PAPER
1.80-1.88 (m, 8H; NBu-H), 1.40-1.50 (m, 8H; NBu-H), 1.47 (s, 18H;
C(CH3)3), 1.44 (s, 18H; C(CH3)3), 1.18 (s, 18H; C(CH3)3), 1.16 (s, 18H;
C(CH3)3), 0.99 (t, 3JH,H = 7.4 Hz, 12H; NBu-H); assignments supported by
1
H-COSY and competition experiments, O-H not located; 13C{1H} NMR
(126 MHz, [D6]Acetone): δ = 170.30, 170.28, 168.36, 165.76, 140.79, 140.46,
140.03, 138.24, 130.43, 130.31, 130.22, 128.61, 128.21, 127.75, 126.86,
126.62, 126.39, 125.95, 118.57, 118.26, 72.59, 71.57, 58.48, 35.50, 35.44,
33.21, 31.32, 31.19, 29.60, 23.51, 19.47, 12.97; MS (ESI, MeOH): m/z =
737.4 [15OH+OMe] (calcd 737.4), 751.4 [15OH+OEt] (calcd 751.4),
765.4 [15OH+OPr] (calcd 765.4), 1461.8 [MOH+OEt] (calcd 1462),
1491.8 [MOH+OBu] (calcd 1490); elemental analysis calcd for
C104H145N5O5Zn2·2H2O: C 72.96, H 8.77, N 4.09; found: C 72.92, H 8.23, N
4.13.
X-ray crystallographic studies: The measured crystals of were stable under
atmospheric conditions; nevertheless they were treated under inert conditions
immersed in perfluoropoly-ether as protecting oil for manipulation. Data
Collection: Measurements were made on a Bruker-Nonius diffractometer
equipped with an APPEX 2 4K CCD area detector, a FR591 rotating anode
with MoK radiation, Montel mirrors and a Kryoflex low temperature device
(T = 173 °C). Full-sphere data collection was used with  and  scans.
Programs used: Data collection Apex2 V2011.3 (Bruker-Nonius 2008), data
reduction Saint + Version 7.60A (Bruker AXS 2008) and absorption
correction SADABS V. 2008-1 (2008). Structure Solution: SHELXTL
Version 6.10 (Sheldrick, 2000)[23] was used. Structure Refinement:
SHELXTL-97-UNIX VERSION.
Crystallographic details for (2)·(CH3CN)4: Formula C96H120N8O4Zn2; Mw =
1580.74; crystal size 0.60 × 0.60 × 0.50 mm3; monoclinic; space group P2(1);
a = 14.0779(5) Å, b = 21.8466(9) Å, c = 14.7791(6) Å;  = 90,  =
105.179(2),  = 90º; V = 4386.8(3) Å3; Z = 2; calcd = 1.197 mg/M3; (MoK)
= 0.601 mm-1; T = 100(2) K; (min/max) = 1.43/36.35º; F(000) = 1688;
38894 reflections collected; 30785 unique reflections (Rint = 0.0370);
absorption correction empirical; refinement method: full-matrix leastsquares on F2; data/restraints/ parameters: 38894/1/1019; GoF on F2 = 0.994;
R1 = 0.0443 and wR2 = 0.1007 [I>2(I) ]; R1 = 0.0630 and wR2 = 0.1072 (all
data); largest diff. peak and hole: 1.124 and 0.583 e3·Å-3; completeness (
= 36.35º) = 98.1%; Flack parameter: x = 0.003(4).

and 0.367 e3·Å-3; completeness ( = 28.686º) = 99.4%; The absorption
correction for this structure was done using the program TWINABS[24] as the
sample consisted of two crystalline domains.
Crystallographic details for assembly 14·(CH3CN)2: Formula
C98H126N8O4Zn2; Mw = 1610.80; crystal size 0.35 × 0.02 × 0.02 mm3;
orthorhombic; space group P2(1)2(1)2(1); a = 11.284(4) Å, b = 24.382(9) Å,
c = 33.548(12) Å;  =  =  = 90º; V = 9230(6) Å3; Z = 4; calcd = 1.159
mg/M3; (MoK) = 0.573 mm-1; T = 100(2) K; (min/max) = 1.670/23.416º;
F(000) = 3448; 166995 reflections collected; 13323 unique reflections (Rint
= 0.2452); absorption correction empirical; refinement method: full-matrix
least-squares on F2; data/restraints/ parameters: 13323/24/1035; GoF on F2
= 1.034; R1 = 0.0906 and wR2 = 0.2108 [I>2(I) ]; R1 = 0.1393 and wR2 =
0.2462 (all data); largest diff. peak and hole: 1.702 and 1.465 e3·Å-3;
completeness ( = 23.416º) = 98.6%; Flack parameter: x = -0.033(18).
Crystallographic
details
for
assembly 15·(acetone):
Formula
C56.69H81.88N2.5O4.06Zn; Mw = 928.74; crystal size 0.30 × 0.15 × 0.15 mm3;
triclinic; space group P1; a = 13.6739(4) Å, b = 16.9639(5) Å, c = 25.4140(8)
Å;  = 85.441(2),  = 77.685(2),  = 71.526(2)º; V = 5462.2(3) Å3; Z = 4;
calcd = 1.129 mg/M3; (MoK) = 0.494 mm-1; T = 100(2) K; (min/max) =
1.517/33.081º; F(000) = 2008; 120861 reflections collected; 64350 unique
reflections (Rint = 0.0465); absorption correction empirical; refinement
method: full-matrix least-squares on F2; data/restraints/ parameters:
64350/1003/2622; GoF on F2 = 0.986; R1 = 0.0549 and wR2 = 0.1315
[I>2(I) ]; R1 = 0.0888 and wR2 = 0.1502 (all data); largest diff. peak and
hole: 1.017 and 0.985 e3·Å-3; completeness ( = 33.081º) = 92.6%; Flack
parameter: x = 0.009(5).

Supporting Information (see footnote on the first page of this article):
Copies of relevant MS and NMR spectra of known and new compounds.
CCDCs 988530-988534 contain the supplementary crystallographic data for
this paper. These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

Acknowledgments

Crystallographic details for 10·(DMSO)2: Formula C32H32N4O8S2Zn; Mw =
730.11; crystal size 0.30 × 0.12 × 0.12 mm3; triclinic; space group P1; a =
9.6549(5) Å, b = 11.6525(6) Å, c = 14.7054(8) Å;  = 80.141(2),  =
83.968(2),  = 89.208(2)º; V = 1620.94(15) Å3; Z = 2; calcd = 1.496 mg/M3;
(MoK) = 0.944 mm-1; T = 100(2) K; (min/max) = 1.41/27.27º; F(000) =
756; 21345 reflections collected; 8527 unique reflections (Rint = 0.0203);
absorption correction empirical; refinement method: full-matrix leastsquares on F2; data/restraints/ parameters: 8527/3/862; GoF on F2 = 1.042;
R1 = 0.0274 and wR2 = 0.0719 [I>2(I) ]; R1 = 0.0281 and wR2 = 0.0725 (all
data); largest diff. peak and hole: 1.097 and 0.447 e3·Å-3; completeness (
= 27.27º) = 83.9%; Flack parameter: x = -0.005(8).

This work was supported by the Spanish Ministry of Science and Innovation
(MICINN) through project CTQ2011-27385, ICREA and ICIQ. We thank
Dr N. Cabello, A. Gonzalez and S. Arnal for the mass spectrometric analyses.
Dr Daniele Anselmo is thanked for experimental assistance concerning
complex 2.

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Crystallographic details for the polymeric side-product during the synthesis
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FULL PAPER

Entry for the Table of Contents:
Key Topic
A convenient method for the synthesis
of a series of chiral Zn(salen)s based on
a 1,2-diphenylethanediamine backbone
has been developed. These complexes
have been used to assemble
multinuclear supramolecular assemblies
of which the solid state and solution
properties were determined. These
chiral Zn(salen)s hold promise as
molecular building blocks with modular
characteristics.

Eddy Martin, Marta Martínez
Belmonte, Eduardo C. EscuderoAdán, and Arjan W. Kleij*[a,b]……..
Page No. – Page No.
Exploring the Building Block Potential
of Readily Accessible Chiral Zn(salen)
Complexes
Keywords: Chiral / salen ligands / SelfAssembly / Synthesis / Zinc

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