Insertion reactions of heterocumulenes with zincocene Cp* 2Zn

Article abstract of DOI:10.1002/zaac.201200061

Zincocene Cp*₂Zn reacts with carbodiimides C(NR) ₂ with insertion into the Zn-Cp* bond and formation of [(Cp*C(NR)₂]₂Zn [R = Et (1), iPr (2), Cy (3)]. In addition, the reaction of Cp*₂Zn with CS₂ under dry conditions gives (Cp*CS₂)₂Zn (4), whereas in the presence of a small amount of water [Zn₄(μ₄-O)(S ₂CCp*)₆] (5) is obtained. Compounds 1-4 were characterized by NMR (¹H, ¹³C) and IR spectroscopy as well as elemental analysis and single-crystal X-ray diffraction (2-4, 5 of poor quality). The solid-state structure of 5 is comparable to the carboxylate complex previously obtained from the reaction of Cp*₂Zn with CO₂. Copyright

Full text of DOI:10.1002/zaac.201200061

ARTICLE
DOI: 10.1002/zaac.201200061
Insertion Reactions of Heterocumulenes with Zincocene Cp*2Zn
Stephan Schulz,*[a] Sarah Schmidt,[a] Dieter Bläser,[a] and Christoph Wölper[a]
Dedicated to Professor Klaus Jurkschat on the Occasion of His 60th Birthday
Keywords: Heterocumulene; Insertion reaction; Zinc; C–C bond formation; X-ray diffraction
Abstract. Zincocene Cp*2Zn reacts with carbodiimides C(NR)2 with
insertion into the Zn–Cp* bond and formation of [(Cp*C(NR)2]2Zn [R
= Et (1), iPr (2), Cy (3)]. In addition, the reaction of Cp*2Zn with CS2
Compounds 1–4 were characterized by NMR (1H, 13C) and IR spec-
troscopy as well as elemental analysis and single-crystal X-ray diffrac-
tion (2–4, 5 of poor quality). The solid-state structure of 5 is compar-
under dry conditions gives (Cp*CS2)2Zn (4), whereas in the presence able to the carboxylate complex previously obtained from the reaction
of a small amount of water [Zn4(μ4-O)(S2CCp*)6] (5) is obtained. of Cp*2Zn with CO2.
site catalysts for the ring-opening polymerization (ROP) of
Introduction
lactide,[6] the epoxide/CO2 copolymerization[7] and the terpo-
The activation of CO2 and its effective utilization as C1-
lymerization of epoxide, cyclic anhydrides, and CO2,[8] zinc
feedstock in organic chemistry is still an ongoing research
dialkyls almost completely failed to react with CO2 with inser-
topic in metal organic chemistry.[1] Unfortunately, due to its
tion into the Zn–C bond. However, we succeeded in the direct
thermodynamic stability and kinetic inertness, only highly nu-
carboxylation reaction of zincocene Cp*2Zn with CO2 in the
cleophilic reagents such as organolithium and Grignard rea-
absence of any transmetalation reagent.[9] The resulting zinc
gents readily react with CO2 with C–C bond formation. More-
oxocarboxylate [Zn4(μ4-O)(O2CCp*)6] contains
a central
over, activation reactions of CO2 by coordination to transition
metal complexes, which lowers the activation energy for fur-
ther reactions, were also studied[2] and carboxylation reactions
of organoboronic acids, organozinc, and organotin reagents
using CO2 were found to be catalyzed by late transition metal
complexes.[3]
Compared to CO2, heterocumulenes such as CS2 and COS
show an enhanced reactivity. Even though both compounds are
neither naturally abundant nor a chemical waste product, their
increased reactivity was expected to be helpful for the develop-
ment of a deeper understanding of the mechanism of C–C bond
formation reactions. Consequently, reactions of main group
metal, transition metal and lanthanide and actinide metal com-
plexes were reported.[4]
We recently became interested in activation reactions of
heterocumulenes with organozinc reagents R2Zn, which have
been established in the past as soft nucleophiles in organic
chemistry. While zinc hydrides, zinc alkoxides, and zinc
amides areknown to reactwith CO2 withinsertion into theZn–H,
Zn–O, and Zn–N bond[5] and therefore serve as living single-
[Zn4O]6+ tetrahedron as was typically observed in basic zinc
acetate,[10] carbonates, and carbamates,[5] phosphates and
phosphonates,[11] as well as in metal organic frameworks
(MOFs) such as MOF-5 and IRMOF-9.[12] Moreover, we re-
ported on reactions of organozinc reagents with various car-
bodiimides, C(NR)2, and isocyanates RNCO,[13] and Carmona
reported on the insertion reaction of CNXyl into the Zn–Cp*
bond of zincocene.[14] Interestingly, bis(phosphinimino)meth-
anide complexes of the type [{(Me3SiNPPh2)2CH}ZnR] (R =
Me, Ph) were reported to react with carbodiimides, ketenes,
and isocyanates via nucleophilic addition of the methine car-
bon atom of the {CH(Ph2PNSiMe3)2} ligand to the hetero-
cumulenes and C–C bond formation.[15]
Herein we report on insertion reactions of carbodiimides as
well as of CS2 with zincocene, Cp*2Zn. The resulting com-
plexes [(Cp*C(NR)2]2Zn [R = Et (1), iPr (2), Cy (3)] and
(Cp*CS2)2Zn (4) were characterized by multinuclear NMR
(1H, 13C) and IR spectroscopy, elemental analyses, and single-
crystal X-ray diffraction.
* Prof. Dr. S. Schulz
Results and Discussion
Fax: +49-201-183 3830
E-Mail: stephan.schulz@uni-due.de
[a] Inorganic Chemistry
A toluene solution of Cp*2Zn reacts with a twofold amount
of RNCNR (R = Et, iPr, Cy) at ambient temperature within 1 h
with insertion of the carbodiimide into the Zn–Cp* bond and
subsequent formation of the corresponding homoleptic
bisamidinate complexes [Cp*C(NR)2]2Zn [R = Et (1), iPr (2),
Cy (3)].
University of Duisburg-Essen
Universitätsstr. 5–7, S07 S03 C30
45117 Essen, Germany
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201200061 or from the au-
thor.
Z. Anorg. Allg. Chem. 2012, 638, (᭿), 1–7
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
1

S. Schulz, S. Schmidt, D. Bläser, C. Wölper
ARTICLE
1
The formation of 1–3 was monitored by in situ H NMR angles (2: 109.73°; 3: 109.43°) are within the typical range
spectroscopy. The progress of the reaction is shown by the previously reported for zinc bisamidinate complexes.[16] The
continuously decreasing resonance of the Zn-bonded Cp* difference in the endo- and exocyclic N–Zn–N angles lead to
¯
groups (δ =1.88 ppm in [D8]toluene). Simultaneously, three an elongation of the coordination tetrahedron along an 4 axis.
new singlet signals with a relative intensity of 1:2:2 steadily The similar values of the geometrical parameters of the central
increases, indicating the formation of σ-bonded Cp* groups. molecule cores prove the steric influence of the organic substit-
Moreover, the 13C NMR spectra of 1–3 each show an ad- uents to be rather limited. 2 and 3 show axial chirality due to
ditional signal at 170.6 (1), 167.9 (2), and 167.8 (3) ppm, the presence of intramolecular CH···π interactions. Since the
respectively, due to the amidinate backbone as was previously space groups of both compounds are centro-symmetric they
observed by us for amidinate and amidate zinc complexes[16,17] are racemic. The asymmetric units were chosen to contain the
(Scheme 1).
R enantiomer. The stability of the conformation in solution was
not investigated. As potential acceptor atoms are well shielded
in the center of the molecule no intermolecular interactions can
be found (shortest intermolecular H···N distance: 3.53 Å in 2
and Ͼ4 Å in 3) and the packing is constituted by most dense
packing alone (Figure 2).
Scheme 1. Synthesis of [Cp*C(NR)2]2Zn.
Single crystals of 2 and 3 were obtained from solutions in
toluene upon storage at –30 °C. Complexes 2 and 3 crystallize
in the monoclinic space group P21/c (2) and P21/n (3), respec-
tively, with four molecules in the unit cell[18] (Figure 1).
Figure 2. Molecular structure of 3. Non-interacting hydrogen atoms
are omitted for clarity. Thermal ellipsoids at 50% probability levels.
Selected bond lengths /Å and angles /°: Zn1–N1 2.0027(11), Zn1–N2
2.0056(11), Zn1–N3 1.9925(11), Zn1–N4 2.0106(11), N1–C45
1.3275(16), N2–C45 1.3410(16), N3–C46 1.3296(16), N4–C46
1.3354(16); N3–Zn1–N1 135.91(5), N3–Zn1–N2 131.50(5), N1–Zn1–
N2 65.91(4), N3–Zn1–N4 65.76(4), N1–Zn1–N4 135.41(5), N2–Zn1–
N4 136.37(5), N1–C45–N2 109.57(11), N3–C46–N4 109.28(11), C45–
N1–Zn1 92.52(8), C45–N2–Zn1 91.98(8), C46–N3–Zn1 92.96(8),
C(33)–N(3)–Zn(1) 135.88(8), C(46)–N(4)–C(39) 134.70(11), C46–
N4–Zn1 91.99(8). CH···π interactions C21–H21···R (C1 C2 C3 C4 C5)
d(H···M) 2.32 Å, d(H···R) 2.3014(13) Å, Ͻ(CHM) 128.8°, Ͻ(HMR)
82.7°, C33–H33···R (C11 C12 C13 C14 C15) d(H···M) 2.28 Å,
d(H···R) 2.2693(14), Ͻ(CHM) 131.4°, Ͻ(HMR) 84.4°.
Figure 1. Molecular structure of 2. Non-interacting hydrogen atoms
are omitted for clarity. Thermal ellipsoids at 50% probability levels.
Selected bond lengths /Å and angles /°: Zn1–N1 2.0087(14), Zn1–N3
2.0110(14), Zn1–N2 2.0175(14), Zn1–N4 2.0212(15) N1–C33
1.336(2), N2–C33 1.345(2), N3–C34 1.345(2), N4–C34 1.328(2); N1–
Zn1–N3 131.65(6), N1–Zn1–N2 65.86(6), N3–Zn1–N2 137.07(6),
N1–Zn1–N4 132.07(6), N3–Zn1–N4 65.75(6), N2–Zn1–N4 138.10(6),
N1–C33–N2 109.49(15), N3–C34–N4 109.97(15), C33–N1–Zn1
92.66(10), C33–N2–Zn1 92.00(10), C34–N3–Zn1 92.06(10), C34–
N4–Zn1 92.13(10). CH···π interactions C21–H21···R (C1 C2 C3 C4
C5) d(H···M) 2.24 Å, d(H···R) 2.2315(19) Å, Ͻ(CHM) 135.0°,
Ͻ(HMR) 85.0°; C30–H30···R (C11 C12 C13 C14 C15) d(H···M)
2.27 Å, d(H···R) 2.2622(19) Å, Ͻ(CHM) 133.8°, Ͻ(HMR) 85.2°.[19]
Since Cp*2Zn was found to react readily with CO2,[9] isocy-
anates CNXyl,[14] RNCO,[17] and RNCNR with insertion into
the Zn–Cp* bond, we became interested in the reaction of zin-
cocene with CS2. Compared to CO2, CS2 was reported to show
an enhanced chemical reactivity. Therefore it came not as a
The zinc atoms are tetrahedrally coordinated by two chelat- surprise, that Cp*2Zn was found to react readily with CS2 at
ing amidinate groups. The Zn–N distances [2: 2.0087(14)– ambient temperature in almost quantitative yield with forma-
2.0212(15) Å; 3: 1.9925(11)–2.0106(11) Å] are almost iden- tion of (Cp*CS2)2Zn (4). Moreover, the presence of a small
tical to those previously observed for bisamidinate com- amount of water yielded [Zn4(μ4-O)(S2CCp*)6] (5) including
plexes.[16] The C–N bond length in the amidinate group are in a central Zn4O core as was previously observed for the reac-
[9]
between the typical values for double (1.29 Å) and single tion of Cp*2Zn with CO2 (Scheme 2).
1
bonds (1.47 Å), clearly indicating a delocalized π-electron sys-
The H NMR spectrum of 4 shows three resonances at δ =
tem as was expected. The average endocyclic N–Zn–N bond 1.48, 1.63, and 1.84 ppm, respectively, due to the presence of
angles (2: 65.81°; 3: 65.84°) are smaller than the exocyclic σ bound Cp* groups. Moreover, the characteristic S=C=S ab-
ones (2: 134.72°; 3: 134.8°) and the average N–C–N bond sorption band in the IR spectrum of CS2 at 1482 cm–1 is shifted
2
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Z. Anorg. Allg. Chem. 2012, 1–7

Insertion Reactions of Heterocumulenes with Zincocene Cp*2Zn
Scheme 2. Synthesis of (Cp*CS2)2Zn (4) and [Zn4(μ4-O)(S2CCp*)6]
(5).
to 1445 (νasym) and 1177 cm–1 (νsym) in 4 as was previously
reported for Me2Al(μ-NiPr2)2Mg(S2CMe) (1142, 1017 cm–1)
[20]
and Cp*W(NO)(η2-S2CNHtBu)(OtBu) (1142, 1017 cm–
1).[21] Unfortunately, the 13C{1H} NMR spectra of 4 and 5 did
not exhibit resonances for the CS2 carbon atoms, which were
expected to be shifted to lower field compared to that of free
CS2 (δ =192.6 ppm). Comparable findings were recently re-
ported.[22] Typically, values far above 200 ppm were re-
ported,[22,23] even though Limberg et al. very recently observed
a resonance at δ = 172.5 ppm for a dinuclear Cu-CS2 com-
plex.[24]
Figure 4. Molecular structure of 5. Due to the poor scattering power
of the crystals only the connectivity could be determined reliably. The
oxygen atom is placed on an inversion center and thus the positions
of the zinc atoms (and probably sulfur atoms) are disordered over two
positions (only one component displayed).
Single crystals of 4 were obtained from thf solution upon
storage at –30 °C.[18] Compound 4, which was obtained as thf
2.3008(6) Å] and one long Zn–S bond toward the axial sulfur
atoms Zn1–S1 2.5785(7); Zn1–S4 2.6965(7) Å], most likely
resulting from the coordination of the thf molecule. The Zn1–
O1 bond length of 2.0335(16) Å is in the typical range for
coordinated thf molecules to tetrahedrally coordinated central
ZnII atoms. The axial S1–Zn1–S4 unit deviates slightly from
linearity [169.66(2)°], whereas S2, S3, O1, and Zn1 are located
on a plane (r.m.s. deviation from best plane 0.0413 Å). How-
ever within the plane the trigonal coordination of Zn1 is dis-
torted towards T-shaped arrangement [S–Zn–O ca. 108°,
S–Zn–S 142.72(2)°] and the S1···S4 vector is not perpendicular
to this plane (72.5°) as in a regular trigonal-bipyramid. This
coordination environment is comparable to those of other zinc
¯
adduct, crystallizes in the P1 space group (Figure 3). In con-
trast, 5 was obtained from a solution in toluene. Unfortunately,
the quality of the crystals was rather low. As a consequence,
the structural parameters of 5 cannot be discussed in detail,
even though the connectivity and composition of the com-
pound was proven (Figure 4).
–
complexes bearing two ligands with a chelating CS2 unit and
a total coordination number of 5. A search in the CSD datab-
ase[25] gave 97 structures matching this fragment, of which 79
adopt a planar arrangement of the equatorial positions (zinc
atoms deviating less than 0.07 Å from the S/S/X plane). The
mean angle between this plane and the vector between the ax-
ial positions is 2° larger than the one observed in 4 (74.4°).
In contrast to 2 and 3, the coordinating atoms in 4 do not
bear any residual groups, hence allowing the establishment of
intermolecular interactions. Two neighboring molecules
Figure 3. Molecular structure of 4·thf. Hydrogen atoms are omitted
for clarity. Thermal ellipsoids at 50% probability levels. Selected bond
lengths /Å and angles /°: Zn1–O1 2.0335(16), Zn1–S1 2.5785(7), Zn1–
S2 2.3197(6), Zn1–S3 2.3008(6), Zn1–S4 2.6965(7), S1–C1 1.664(2), (–x+1, –y+1, –z+1) show short S···S contacts, whose lengths
S2–C1 1.697(2), S3–C2 1.7045(19), S4–C2 1.668(2); O1–Zn1–S3
either equal approximately the sum of the van der Waals radii
107.98(5), O1–Zn1–S2 108.70(5), S3–Zn1–S2 142.72(2), O1–Zn1–S1
or are about 0.3 Å shorter, respectively [3.3261(12) Å,
96.45(6), S3–Zn1–S1 109.76(2), S2–Zn1–S1 72.41(2), O1–Zn1–S4
3.6556(9) Å]. A CH···S hydrogen bond [C20–H20A···S3 (–x,
92.83(6), S3–Zn1–S4 71.38(2), S2–Zn1–S4 100.29(2), S1–Zn1–S4
–y+1, –z+1), d(H···A) 2.98 Å, Ͻ(DHA) 141.8°] connects these
dimers to form chains parallel to a (Figure 5).
169.66(2), C1–S1–Zn1 80.35(7), C1–S2–Zn1 87.94(7), C2–S3–Zn1
89.81(7), C2–S4–Zn1 77.93(7), S1–C1–S2 119.30(11), S4–C2–S3
120.88(11).
The central zinc atom in 4 is coordinated by two chelating
thiocarboxylate groups and a single thf molecule, hence re-
sulting in a distorted trigonal-bipyramidal coordination mode.
Conclusions
We have demonstrated that zincocene readily reacts with
The thiocarboxylate groups each show one short Zn–S bond heterocumulenes such as carbodiimides and carbon disulfide
toward the equatorial sulfur atoms [Zn1–S2 2.3197(6); Zn1–S3 with insertion into the Zn–Cp* bond and subsequent formation
Z. Anorg. Allg. Chem. 2012, 1–7
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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3

S. Schulz, S. Schmidt, D. Bläser, C. Wölper
ARTICLE
(75 MHz, C6D6, 25 °C): δ = 11.0 (C5Me5), 11.4 (C5Me5), 24.6
(C5Me5), 28.6 [NCH(CH3)2], 28.7 [NCH(CH3)2], 43.7 [NCH(CH3)2],
45.4 [NCH(CH3)2], 65.7 (C5Me5), 134.0 (C5Me5), 135.0 (C5Me5),
167.9 (CN2). IR: ν˜ = 2961, 2921, 2847, 1645, 1480, 1426, 1368, 1318,
1281, 1261, 1239, 1211, 1134, 1096, 1061, 969, 888, 803, 700, 675,
508 cm–1.
3: Yield 0.70 g (93%). Melting point: Ͼ220 °C. Anal. Found (calcd)
for C46H74N4Zn (748.46): H 11.0 (10.9), C 74.0 (73.8), N 7.5 (7.5)%.
1H NMR (300 MHz, C6D6, 25 °C): δ = 1.14–1.44 (m, 12 H, CH2),
1.40 (s, 6 H, C5Me5), 1.56–1.68 (m, 4 H, CH2), 1.71 (s, 12 H, C5Me5),
1.76–1.88 (m, 2 H, CH2), 1.98 (s, 12 H, C5Me5), 2.19 (m, 2 H, CH2),
2.94 (m, 1 H, CHax), 4.04 (m, 1 H, CHax). 13C{1H} NMR (75 MHz,
C6D6, 25 °C): δ = 11.1 (C5Me5), 11.2 (C5Me5), 11.3 (C5Me5), 24.4
(CH2), 26.6 (CH2), 26.7 (CH2), 38.4 (CH2), 38.5 (CH2), 39.7 (CH2),
39.8 (CH2), 52.0 (NCH), 52.4 (NCH), 65.7 (C5Me5), 134.1 (C5Me5),
143.5 (C5Me5), 143.6 (C5Me5), 167.8 (CN2). IR: ν˜ = 2916, 2847,
1421, 1353, 1340, 1294, 1257, 1237, 1202, 1081, 1062, 1027, 990,
898, 887, 803, 663, 569, 541, 504 cm–1.
Figure 5. Intermolecular interactions in the packing of 4.
of homoleptic bisamidinate and bis(thio)carboxylate com-
plexes. The potential capability of 4 to serve as single source
precursor for the solution-based and gas-phase based
(MOCVD) formation of ZnS is currently investigated.
(Cp*CS2)2Zn (4): CS2 (0.08 g, 1 mmol) was added dropwise to a solu-
tion of Cp*2Zn (0.17 g, 0.5 mmol) in toluene (15 mL) and stirred for
2 h at ambient temperature. The solvent was removed in vacuo and
the solid residue was dissolved in 5 mL of thf. Yield 0.23 g (83%).
Melting point: Ͼ220 °C. Anal. Found (calcd) for C22H30S4Zn*C4H8O
(560.17): H 6.9 (6.8), C 55.9 (55.7)%. 1H NMR (300 MHz, C6D6,
25 °C): δ = 1.48 (s, 3 H, C5Me5), 1.63 (s, 6 H, C5Me5), 1.84 (s, 6 H,
C5Me5). 13C{1H} NMR (75 MHz, C6D6, 25 °C): δ = 11.0 (C5Me5),
11.4 (C5Me5), 21.3 (C5Me5), 77.9 (C5Me5), 125.7 (C5Me5), 137.8
(C5Me5). IR: ν˜ = 2929, 2906, 2825, 1445, 1261, 1157, 1096, 1013,
813, 799, 671, 544 cm–1.
Experimental Section
General: All manipulations were performed in an argon atmosphere.
Cp*2Zn was prepared according to literature methods.[26] 1H, 13C{1H}
NMR spectra were recorded with a Bruker DMX 300 spectrometer
and are referenced to internal C6D5H (1H: δ = 7.154; 13C: δ =
128.0 ppm). IR spectra were recorded with an ALPHA-T FT-IR spec-
trometer equipped with a single reflection ATR sampling module.
Melting points were measured in sealed capillaries and were not cor-
rected. Elemental analyses were performed at the elemental analysis
laboratory of the University of Essen.
Orange crystals of 4·thf were isolated after storage of a solution of 4
in thf for 12 h at –30 °C.
[Zn4(μ4-O)(S2CCp*)6] (5): CS2 (0.31 g, 4 mmol) was added dropwise
to Cp*2Zn (0.34 g, 1.0 mmol) dissolved in toluene (15 mL) and stirred
for 10 min at ambient temperature. Afterwards, water (4.5 μL,
0.25 mmol) was added and the resulting solution stirred for additional
2 h. Colorless crystals of 5, which were not suitable for a full crystallo-
graphic analysis,[18] were formed within 24 h upon storage at –30 °C.
Yield 0.11 g (28%). Melting point: Ͼ220 °C. Anal. Found (calcd) for
C66H90OS12Zn4 (1545.69): H 6.1 (5.9), C 52.6 (51.3)%. 1H NMR
(300 MHz, C6D6, 25 °C): δ = 1.49 (s, 3 H, C5Me5), 1.62 (s, 6 H,
C5Me5), 1.85 (s, 6 H, C5Me5). 13C{1H} NMR (75 MHz, C6D6, 25 °C):
δ = 10.6 (C5Me5), 10.9 (C5Me5), 11.7 (C5Me5), 79.8 (C5Me5), 138.0
(C5Me5), 143.7 (C5Me5). IR: ν˜ = 2966, 2913, 2852, 1656, 1600, 1495,
1437, 1379, 1363, 1260, 1227, 1145, 1072, 999, 955, 868, 789, 729,
709, 660, 646, 616, 600, 531, 465 cm–1.
[Cp*C(NR)2]2Zn (1–3): Solutions of Cp*2Zn (0.34 g, 1 mmol) and
two equivalents of carbodiimide RNCNR were dissolved in toluene
(10 mL) and stirred for 1 h at ambient temperature. Colorless crystals
of [Cp*C(NR)2]2Zn [R = Et (1), iPr (2), Cy (3)] were formed within
12 h after storage at –30 °C.
1: Yield 0.49 g (94%). Melting point: Ͼ220 °C. Anal. Found (calcd)
for C30H50N4Zn (540.19): H 10.8 (10.8), C 66.6 (66.7), N 10.3
3
(10.4)%. 1H NMR (300 MHz, C6D6, 25 °C): δ = 1.11 (t, JHH
=
7.1 Hz, 6 H, CH2CH3), 1.31 (t, 3JHH = 7.1 Hz, 6 H, CH2CH3), 1.40 (s,
6 H, C5Me5), 1.65 (s, 12 H, C5Me5), 1.88 (s, 12 H, C5Me5), 2.80 (q,
3JHH = 7.1 Hz, 4 H, CH2CH3), 3.64 (q, JHH = 7.0 Hz, 4 H, CH2CH3).
3
13C{1H} NMR (75 MHz, C6D6, 25 °C): δ = 10.9 (C5Me5), 11.0
(C5Me5), 19.4 (C5Me5), 20.5 (NCH2CH3), 23.9 (NCH2CH3), 38.0
(NCH2CH3), 42.2 (NCH2CH3), 65.2 (C5Me5), 134.5 (C5Me5), 141.5
(C5Me5), 170.6 (CN2). IR: ν˜ = 2961, 2919, 2849, 1657, 1457, 1480,
1427, 1369, 1341, 1320, 1283, 1260, 1238, 1210, 1134, 1096, 1063,
1034, 965, 890, 803, 759, 700, 674, 596, 510 cm–1.
X-ray crystallographic data of 1 are given in the Supporting Infor-
mation. Crystallographic data (excluding structure factors) for the
structures in this paper have been deposited with the Cambridge Crys-
tallographic Data Centre, CCDC, 12 Union Road, Cambridge
CB21EZ, UK. Copies of the data can be obtained free of charge on
quoting the depository numbers CCDC-865384 (2), CCDC-865383
(3), and CCDC-865385 (4) (Fax: +44-1223-336-033; E-Mail:
deposit@ccdc.cam.ac.uk, http://www.ccdc.cam.ac.uk).
2: Yield 0.57 g (97%). Melting point: Ͼ220 °C. Anal. Found (calcd)
for C34H58N4Zn (588.21): H 9.9 (9.9), C 69.4 (69.4), N 9.5 (9.5)%.
3
1H NMR (300 MHz, C6D6, 25 °C): δ = 1.00 [d, JHH = 5.9 Hz, 6 H,
3
3
CH(CH3)2], 1.03 [d, JHH = 6.0 Hz, 6 H, CH(CH3)2], 1.31 [d, JHH
5.9 Hz, 6 H, CH(CH3)2], 1.33 [d, 3JHH = 5.9 Hz, 6 H, CH(CH3)2], 1.45 Supporting Information (see footnote on the first page of this article):
(s, 6 H, C5Me5), 1.67 (s, 12 H, C5Me5), 1.95 (s, 12 H, C5Me5), 3.38 X-ray crystallographic data of 2, 3, and 4 are given in the Supporting
[sept, 2 H, CH(CH3)2], 4.44 [sept, 2 H, CH(CH3)2]. 13C{1H} NMR Information.
=
4
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© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2012, 1–7

Insertion Reactions of Heterocumulenes with Zincocene Cp*2Zn
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Acknowledgement
S. Schulz thanks the Deutsche Forschungsgemeinschaft (DFG) and the
University of Duisburg-Essen for financial support.
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group P21/c; a = 17.6478(4), b = 13.5140(4), c = 15.6798(4) Å;
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ρ
calcd. = 1.125 g·cm–3; 48455 reflexes (2θmax = 55°), 7688 unique
(Rint = 0.0306); 353 parameters; largest max./min. in the final
difference Fourier synthesis 1.516 e·Å–3 [0.87 Å from
Zn(1)]/–0.282 e·Å–3; max./min. transmission 0.75/0.64; R1
=
0.0354 [I Ͼ 2σ(I)], wR2 (all data) = 0.0972. 3: C46H74N4Zn, M
= 748.46, colorless crystal (0.28ϫ0.25ϫ0.17 mm); monoclinic
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10623 unique (Rint = 0.0189); 460 parameters; largest max./min.
in the final difference Fourier synthesis 0.403 e·Å–3/–0.266 e·Å–3;
max./min. transmission 0.75/0.67; R1 = 0.02327[I Ͼ 2σ(I)], wR2
(all data) = 0.0878. The ADP of C37 and C38 indicates severe
disorder which could not be resolved. 4: C26H38OS4Zn, M =
560.17, orange crystal (0.37ϫ0.25ϫ0.07 mm); triclinic, space
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¯
group P1; a = 8.7117(13), b = 11.1680(17), c = 15.319(2) Å; α =
75.571(7)°, β = 83.278(7)°, γ = 87.783(7)°, V = 1433.4(4) Å3; Z
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¯
orange block (0.15ϫ0.13ϫ0.08 mm); triclinic, space group P1;
a = 11.9105(7) Å, b = 12.5796(7) Å, c = 15.3242(9) Å; α =
103.415(3)°, β = 90.586(3)°, γ = 108.541(3)°, V = 2108.6(2) Å3;
Z = 1. The scattering power of the crystals was poor (2θmaxϽ
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Z. Anorg. Allg. Chem. 2012, 1–7
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
5

S. Schulz, S. Schmidt, D. Bläser, C. Wölper
ARTICLE
However the data were sufficient to establish the connectivity of
the molecule.
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Received: February 15, 2012
Published Online: ᭿
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Z. Anorg. Allg. Chem. 2012, 1–7

Insertion Reactions of Heterocumulenes with Zincocene Cp*2Zn
S. Schulz,* S. Schmidt, D. Bläser, C. Wölper .................. 1–7
Insertion Reactions of Heterocumulenes with Zincocene
Cp*2Zn
Z. Anorg. Allg. Chem. 2012, 1–7
© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
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