Synthesis and structures of selected triazapentadienate of Li, Mn, Fe, Co, Ni, Cu(I), and Cu(II) using 2,4-N,N′-disubstituted 1,3,5- triazapentadienate anions as ancillary ligands: [N(Ar)C(NMe2) NC(NMe2)-N(R)]- (Ar = Ph, 2,6-iPr 2-C6H3; R = H, SiMe3)

Article abstract of DOI:10.1021/ic800320e

Addition reaction of ArN(SiMe₃)M (Ar = Ph or 2,6- ⁱPr₂-C₆H₃ (Dipp); M = Li or Na) to 2 equivalents of α-hydrogen-free nitrile RCN (R = dimethylamido) gave the dimeric [M{N(Ar)C(NMe₂)NC(NMe₂)N(SiMe₃)}] ₂ (1a, Ar = Ph, M = Li; 1b, Ar = Ph, M = Na; 1c, Ar = Dipp, M = Li). 1d was obtained by hydrolysis of 1c at ambient temperature. Treatment of a double ratio of 1a or 1b with anhydrous MCl₂ (M = Mn, Fe, Co) yielded the 1,3,5-triazapentadienato complexes [M{N(Ph)C(NMe₂)NC(NMe ₂)N(SiMe₃)}₂] (M = Mn, 2; Fe, 3; Co, 4) and with NiCl₂·6H₂O gave [M{N(Ph)C(NMe ₂)NC(NMe₂)N(H)}₂] (M = Ni, 5). Treatment of an equiv of 1c with anhydrous CuCl in situ and in air led to complexes [{N(DiPp)C(NMe₂)NC(NMe₂)N(SiMe₃)}CuPPh ₃] 6 and [Cu{N(Dipp)C(NMe₂)NC(NMe₂)N(H)} ₂] 7, respectively. 1c, 1d, and 2-7 were characterized by X-ray crystallography and microanalysis. 1c, 1d, 5, and 6 were well characterized by ¹H, ¹³C NMR, 1c by ⁷Li, and 6 by ³¹P NMR as well. The structural features of these complexes were described in detail.

Full text of DOI:10.1021/ic800320e

Inorg. Chem. 2008, 47, 6692-6700
Synthesis and Structures of Selected Triazapentadienate of Li, Mn, Fe,
Co, Ni, Cu(I), and Cu(II) using 2,4-N,N′-Disubstituted
1,3,5-Triazapentadienate Anions as Ancillary Ligands: [N(Ar)C(NMe2)NC(NMe2)-
N(R)]- (Ar ) Ph, 2,6-iPr2-C6H3; R ) H, SiMe3)
Meisu Zhou,*,† Yanping Song,† Tao Gong,† Hongbo Tong,† Jianping Guo,† Linhong Weng,‡
and Diansheng Liu†
Institute of Applied Chemistry, Shanxi UniVersity, Taiyuan 030006, People’s Republic of China,
and Department of Chemistry, Fudan UniVersity, Shanghai, People’s Republic of China
Received February 21, 2008
Addition reaction of ArN(SiMe3)M (Ar ) Ph or 2,6-iPr2-C6H3 (Dipp); M ) Li or Na) to 2 equivalents of R-hydrogen-
free nitrile RCN (R ) dimethylamido) gave the dimeric [M{N(Ar)C(NMe2)NC(NMe2)N(SiMe3)}]2 (1a, Ar ) Ph, M ) Li;
1b, Ar ) Ph, M ) Na; 1c, Ar ) Dipp, M ) Li). 1d was obtained by hydrolysis of 1c at ambient temperature.
Treatment of a double ratio of 1a or 1b with anhydrous MCl2 (M ) Mn, Fe, Co) yielded the 1,3,5-triazapentadienato
complexes [M{N(Ph)C(NMe2)NC(NMe2)N(SiMe3)}2] (M ) Mn, 2; Fe, 3; Co, 4) and with NiCl2 ·6H2O gave
[M{N(Ph)C(NMe2)NC(NMe2)N(H)}2] (M ) Ni, 5). Treatment of an equiv of 1c with anhydrous CuCl in situ and in
air led to complexes [{N(Dipp)C(NMe2)NC(NMe2)N(SiMe3)}CuPPh3] 6 and [Cu{N(Dipp)C(NMe2)NC(NMe2)N(H)}2] 7,
respectively. 1c, 1d, and 2-7 were characterized by X-ray crystallography and microanalysis. 1c, 1d, 5, and 6
1
7
were well characterized by H, 13C NMR, 1c by Li, and 6 by 31P NMR as well. The structural features of these
complexes were described in detail.
Introduction
1,5-diazapentadienyl (also known as ꢀ-diketiminate, 1) and
1,3,5-triazapentadienato anions are the acyclic analogues of
C5H5- that contain heteroatoms. The five-membered conju-
gated π system has attracted increasing attention because of
its synthetic utility in organic and organometallic chemistry
and theoretical interest in coordination chemistry.1,2 For 1,5-
diazapentadienyl ligands 1, it has been used in the stabiliza-
tion of low-valent, low-coordinate main-group and transition-
metal adducts,3,4 and some of their transition-metal complexes
are used as catalysts for the polymerization of olefin.5
The 1,3,5-triazapentadienato ligand 2 is also valuable as
a spectator ligand because it is generally firmly bound to
the metals by the donor nitrogen atoms; its steric and
electronic properties of the ligand can be fine-tuned by
variation of the substitutes R1∼R4; and three nitrogen atoms
in the backbone NCNCN provide the possibility of a variety
of bonding modes to metals by adopting W-(κ1-bonded on
the central nitrogen or one of the terminal nitrogen atoms)
or U-shaped (κ2-bonded) conformations.2,6–9 In many recent
* To whom correspondence should be addressed. E-mail: mszhou@
sxu.edu.cn. Tel: +86-351-7010722. Fax: +86-351-7016048.
†
Shanxi University.
Fudan University.
‡
(5) Zhou, M.-S.; Huang, S.-P.; Weng, L.-H.; Sun, W.-H.; Liu, D.-S. J.
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2003, 122, 175–182.
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6692 Inorganic Chemistry, Vol. 47, No. 15, 2008
10.1021/ic800320e CCC: $40.75  2008 American Chemical Society
Published on Web 07/09/2008

Synthesis and Structures of Selected Triazapentadienate
publications, the motivation to make 1,3,5-triazapentadienes
or their metal complexes was governed by highly fluorinated
substituents.10,11 These perfluoroalkyl groups have been used
to improve the thermal stability, oxidative resistance, volatil-
ity, and fluorocarbon solubility of metal adducts.12 These
fluorinated triazapentadienyl ligands include [N{(C3F7)-
C(H)N}2]-,13 [N{(C3F7)C(2,4,6-Me3C6H2)N}2]-,11 [N{(C3-
F7)C(Ph)N}2]-,8,14 [N{(C3F7)C(Dipp)N}2]-,7,15 [N{(C3-
F7)C(C6F5)N}2]-, and [N{(C3F7)C(2-F,6-(CF3)C6H3)N}2]-.10
Several neutral nonfluorinated triazapentadienyl ligands and
their mononuclear metal complexes, homo- or heterotri-
nuclear clusters, were isolated.16–18 Other related reports
concerned[RNC(H)NC(H)NC(H)CHR]-and[RNC(H)NC(H)NC(H-
)NR]- (R ) SiMe3).19,20 Recently, we described the synthesis
of nonsymmetric guanidinato ligands and their metal com-
plexes via the reaction of ArN(SiMe3)Li (Ar ) Ph or 2,6-
iPr2-C6H3) and R-hydrogen-free nitriles.21,22 A new system
of 2,4-disubstituted 1,3,5-triazapentadienyl ligands
[RNC(NMe2)NC(NMe2)NR]- (R ) SiMe3) having two
guanidinato moieties was developed and used in the isolation
of copper(I) complexes.23 In this article, we report our
proceeding studies on addition reaction of PhN(SiMe3)M (M
) Li or Na) or (Dipp)N(SiMe3)Li with 2 equiv of R-hydrogen-
free dimethylcyanamide, which led to in situ synthesis of
1,3,5-triazapentadienato ligands [N(Ar)C(NMe2)NC(NMe2)-
N(R)]- and further to their derived transition-metal com-
plexes. They are: [M{ArNC(NMe2)NC(NMe2)N(SiMe3)}]2
(1a, Ar ) Ph, M )Li; 1b, Ar ) Ph, M ) Na; 1c, Ar )
Dipp, M ) Li), [N(Dipp)C(NMe2)NC(NMe2)NH2] 1d,
M{N(Ph)C(NMe2)NC(NMe2)N(SiMe3)}2 (M ) Mn, 2; Fe,
3; Co, 4); Ni{N(Ph)C(NMe2)NC(NMe2)N(H)}2 5,
{N(Dipp)C(NMe2)NC(NMe2)N(SiMe3)}CuPPh3 6, and
Cu{N(Dipp)C(NMe2)NC(NMe2)N(H)}2 7. The NCNCN
ligand backbone in 1c and 1d adopted a W-shaped config-
uration, and showed short-long-long-short and short-
long-short-long C-N bond distance pattern, respectively;
whereas in 2-7 the NCNCN backbone adopted a U-shaped
configuration. Tetrahedral structures were found for 2, 3, 4
and 7. Square-planar structure was observed for the Ni(II)
complex 5. Three-coordinate Cu(I) atom in 6 featured a
trigonal planar environment.
Experimental Section
General Procedures. All manipulations were carried out under
an atmosphere of argon using standard Schlenk techniques. Solvents
were purchased from commercial sources. Deuterated solvents C6D6
and CDCl3 were dried over activated molecular sieves (4 Å) and
vacuum transferred before use. Hexane was dried using sodium-
potassium alloy. Diethyl ether was dried and distilled from sodium/
benzophenone and stored over a sodium mirror under argon.
Dichloromethane was distilled from activated molecular sieves (4
Å) or CaH2. Glassware was oven-dried at 150 °C overnight. The
NMR spectra were recorded on a Bruker DKX-300 instrument, and
solvent resonances were used as the internal references for 1H
spectra and 13C spectra. Melting points were measured in sealed
capillaries and are uncorrected. Elemental analyses were carried
out using a Vario EL-III analyzer (Germany).
Preparations.
[N(Dipp)C(NMe2)NC(NMe2)N(SiMe3)Li]2
(1c). (CH3)2NCN (0.42 mL, 5.24 mmol) was added to a solution
of (Dipp)N(Li)SiMe3 (0.67 g, 2.62 mmol) in Et2O (30 cm3) at -78
°C. The resulting mixture was warmed to ca. 25 °C and stirred for
overnight. The mixture was concentrated in vacuo to ca. 10 cm3
and set aside at room temperature for 2 d to give colorless crystals
of 1c (0.45 g, 60%). Mp: 149∼151 °C. Found: C, 63.70; H, 9.66;
N, 16.50. C46H86Li2N10Si2O requires C, 63.85; H, 10.02; N, 16.19%.
1H NMR (C6D6): δ 0.55 (s, 18 H, SiMe3), 1.05-1.49 (d, 24 H,
CH(CH3)2), 1.07-1.22, 3.30-3.36 (Et2O), 2.38-2.81 (m, 24
H, N(CH3)2), 3.18-3.49 (sep, 4 H, CH(CH3)2), 7.12∼7.15 (m, 6
H, Ph). 13C NMR (C6D6): δ 4.92 (SiMe3), 16.3 (Et2O), 23.0, 23.6,
24.4, 26.2 (CH(CH3)2), 28.5, 29.6 (CH(CH3)2), 39.4 (N(CH3)2), 66.6
(Et2O), 123.0 (p-CAr), 123.5 (m-CAr), 141.0, 141.7 (o-CAr),
7
146.7(Cipso), 161.7, 163.9 (NCN). Li NMR (C6D6): δ 2.05, 2.36.
[N(Dipp)C(NMe2)NC(NMe2)NH2] (1d). (CH3)2NCN (0.38 mL,
4.74 mmol) was added to a solution of (Dipp)N(Li)SiMe3 (0.61 g,
2.37 mmol) in Et2O (30 cm3) at -78 °C. The resulting mixture
was warmed to ca. 25 °C and stirred for overnight. Diethyl ether
solution (10 mL) of distilled water (0.09 mL, 4.74 mmol) was added
slowly via a syringe at room temperature. After overnight reaction,
the pale-yellow mixture was filtered. The filtrate was concentrated
in vacuo to ca. 10 cm3 and left at room temperature for 3 d to give
colorless crystals of 1d (0.45 g, 60%). Found: C, 67.80; H, 10.04;
N, 22.09. Anal. Calcd for C18H31N5: C, 68.10; H, 9.84; N, 22.06%.
1H NMR (CDCl3): δ 1.04∼1.32 (d, 12 H, CH(CH3)2), 2.66, 2.87
(d, 12 H, NMe), 3.0∼3.3 (sep, 2 H, CH(CH3)2), 4.04 (s, 2 H, NH2),
6.8∼7.4 (m, 3 H, m- and p-Ar). 13C NMR (CDCl3): δ 22.1∼24.0
(m, CH(CH3)2), 27.3, 28.2 (d, CH(CH3)2), 36.0, 38.4 (d, N(CH3)2),
121.6 (p-CAr), 122.8, 124.3 (m-CAr), 138.6, 139.3 (o-CAr), 147.2
(Cipso), 154.9 (NC(NMe2)NH2) 155.7 ((Dipp)NC(NMe2)N).
[N(Ph)C(NMe2)NC(NMe2)N(SiMe3)]2Mn (2). (CH3)2NCN (0.53
mL, 6.52 mmol) was added to a solution of PhN(Li)SiMe3 (0.56
g, 3.26 mmol) in Et2O (30 mL) at -78 °C. The resulting mixture
was warmed to ca. 25 °C and stirred for overnight. MnCl2 (0.21 g,
1.63 mmol) was added at -78 °C. The resulting mixture was
warmed to ca. 25 °C and stirred for 24 h. The volatiles were
removed in vacuo, and the residue was extracted with dichlo-
romethane and filtered. The filtrate was concentrated in vacuo to
ca. 15 cm3 and stored at -25 °C for several days, yielding colorless
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J. Chem. Soc., Dalton Trans. 1994, 3615–3620. (b) Aris, D. R.; Barker,
J.; Phillips, P. R.; Alcock, N. W.; Wallbridge, M. G. H. J. Chem.
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(14) Siedle, A. R.; Webb, R. J.; Behr, F. E.; Newmark, R. A.; Weil, D. A.;
Erickson, K.; Naujok, R.; Brostrom, M.; Mueller, M.; Chou, S.-H.;
Young, V. G. Inorg. Chem. 2003, 42, 932–934.
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(16) Guo, J.-P.; Wong, W.-K.; Wong, W.-Y. Eur. J. Inorg. Chem. 2004,
267–275.
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3634–3640.
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M.-L. Inorg. Chem. 2007, 46, 9548–9557.
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1997, 2091–2092.
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Dalton Trans. 1999, 4041–4046.
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2007, 692, 5195–5202.
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Inorganic Chemistry, Vol. 47, No. 15, 2008 6693

Zhou et al.
Table 2. Selected Bond Lengths (Angstroms) and Angles (Degrees) for
1c and 1d
1c
Li(1)sN(1)
Li(1)sN(3)
Li(1)sN(6)
Li(1)sN(8)
N(1)sC(2)
N(2)sC(2)
N(3)sC(2)
N(3)sC(4)
N(4)sC(4)
N(5)s C(4)
N(3)sLi(1)sN(8) 100.1(3)
N(3)sLi(2)sN(8) 100.9(3)
Li(1)sN(3)sLi(2) 79.5(3)
Li(1)sN(8)sLi(2) 79.5(3)
Li(1)sN(1)sC(2) 92.1(2)
Li(1)sN(6)sC(3) 91.7(3)
Li(2)sN(5)sC(4) 90.5(3)
Li(2)sN(10)sC(9) 90.7(3)
1.998(6)
2.111(6)
2.005(5)
2.106(7)
1314(5)
1.359(3)
1.370(5)
1.374(5)
1.361(4)
1.304(5)
Li(2)sN(3)
Li(2)sN(5)
Li(2)sN(8)
Li(2)sN(10)
N(6)sC(3)
N(7)sC(3)
N(8)sC(3)
N(8)sC(9)
N(9)sC(9)
N(10)sC(9)
N(1)sC(2)sN(3)
N(3)sC(4)sN(5)
N(6)sC(3)sN(8)
N(8)sC(9)sN(10) 116.3(2)
N(1)sLi(1)sN(3) 66.3(2)
N(6)sLi(1)sN(8) 66.3(2)
N(3)sLi(2)sN(5) 66.1(3)
N(8)sLi(2)sN(10) 67.3(2)
2.094(7)
2.037(6)
2.098(6)
2.012(6)
1.315(5)
1.362(4)
1.366(4)
1.368(4)
1.373(4)
1.313(4)
113.9(2)
116.3(3)
114.1(3)
1d
C(1)sN(1)
C(13)sN(1)
C(13)sN(2)
C(13)sN(3)
1.416(2)
1.288(2)
1.388(2)
1.379(3)
N(3)sC(16)
N(4)sC(16)
N(5)sC(16)
1.311(3)
1.360(3)
1.346(3)
C(1)sN(1)sC(13) 119.01(16) C(13)sN(3)sC(16) 122.27(17)
N(1)sC(13)sN(2) 118.06(18) N(3)sC(16)sN(4) 124.38(19)
N(1)sC(13)sN(3) 124.03(17) N(3)sC(16)sN(5) 118.42(19)
N(2)sC(13)sN(3) 117.84(17) N(4)sC(16)sN(5) 117.1(2)
crystals of 2 (0.46 g, 42%). Mp: 130∼132 °C. Found: C, 54.72; H,
8.04; N, 20.91. C30H52N10Si2Mn requires C, 54.27; H, 7.89; N,
21.10%.
[N(Ph)C(NMe2)NC(NMe2)N(SiMe3)]2Fe (3). (CH3)2NCN (0.52
mL, 6.48 mmol) was added to a solution of PhN(Na)SiMe3 (0.61
g, 3.24 mmol) in Et2O (30 cm3) at -78 °C. The resulting mixture
was warmed to ca. 25 °C and stirred for overnight. FeCl2 (0.21 g,
1.62 mmol) was added at -78 °C. The resulting mixture was
warmed to ca. 25 °C and stirred for 24 h, filtered, and the filtrate
was concentrated in vacuo to ca. 15 cm3 and cooled at -25 °C for
3 d, yielding yellow crystals of 3 (0.52 g, 49%). Mp: 98 °C
(decomp.). Found: C, 53.99; H, 7.48; N, 21.13. C30H52N10Si2Fe
requires C, 54.20; H, 7.88; N, 21.07%.
[N(Ph)C(NMe2)NC(NMe2)N(SiMe3)]2Co (4). (CH3)2NCN (0.41
mL, 5.08 mmol) was added to a solution of PhN(Na)SiMe3 (0.48
g, 2.54 mmol) in Et2O (30 cm3) at -78 °C. The resulting mixture
was warmed to ca. 25 °C and stirred for overnight. CoCl2 (0.17 g,
1.27 mmol) was added at -78 °C. The resulting mixture was
warmed to ca. 25 °C and stirred for 24 h, filtered, and the filtrate
was concentrated in vacuo to ca. 10 cm3 and left at room
temperature for several days, yielding purple crystals of 4 (0.57 g,
67%). Mp: 110∼112 °C. Found: C, 54.07; H, 7.39; N, 21.06.
C30H52N10Si2Co requires C, 53.95; H, 7.85; N, 20.97%.
[N(Ph)C(NMe2)NC(NMe2)N(H)]2Ni (5). (CH3)2NCN (0.37 mL,
4.62 mmol) was added to a solution of PhN(Na)SiMe3 (0.43 g,
2.31mmol) in Et2O (30 cm3) at -78 °C. The resulting mixture was
warmed to ca. 25 °C and stirred for overnight. NiCl2 ·6H2O (0.28
g, 1.16 mmol) was added at -78 °C. The resulting mixture was
warmed to ca. 25 °C and stirred for 24 h, filtered, and the filtrate
was concentrated in vacuo to ca. 10 cm3 and left at room
temperature for several days, yielding red crystals of 5 (0.23 g,
38%) in air. Mp: 161∼163 °C. Found: C, 54.85; H, 6.93; N, 26.11.
C24H36N10Ni requires C, 55.08; H, 6.93; N, 26.77%. 1H NMR
(CDCl3): δ 2.55∼3.11 (m, 24 H, NMe), 6.4 (s, 2 H, NH), 6.95∼7.35
(m, 10 H, Ph). 13C NMR (CDCl3): δ 39.8, 40.6, 41.9, 42.9 (NMe),
6694 Inorganic Chemistry, Vol. 47, No. 15, 2008

Synthesis and Structures of Selected Triazapentadienate
(Li)SiMe3 (0.64 g, 2.51 mmol) in Et2O (30 cm3) at -78 °C. The
resulting mixture was warmed to ca. 25 °C and stirred for overnight.
CuCl (0.25 g, 2.51 mmol) and PPh3 (0.66 g, 2.51 mmol) were added
at -78 °C. The resulting mixture was allowed to warm to ca. 25
°C and stirred for 10 h. The volatiles were removed in vacuo, and
the residue was extracted with dichloromethane and filtered. The
filtrate was concentrated in vacuo to ca. 15 cm3 and cooled at -25
°C for 2 d, yielding colorless crystals of 6 (0.75 g, 42%). Mp:
154∼156 °C. Found: C, 60.34; H, 6.81; N, 9.28. C40H55Cl2N5PSiCu
Table 3. Selected Bond Lengths (Angstroms) and Angles (Degrees) for
2-5
2
MnsN(1)
MnsN(5)
MnsN(6)
MnsN(10)
N(1)sMnsN(5)
2.096(4) N(1)sC(7)
2.076(4) N(3)sC(7)
2.074(4) N(3)sC(10)
2.103(4) N(5)sC(10)
92.85(15) N(6)sMnsN(10) 93.02(15)
117.8(3)
1.343(6)
1.324(5)
1.328(5)
1.335 (5)
C(7)sN(3)sC(10) 127.3(4) MnsN(1)sC(7)
N(1)sC(7)sN(3) 125.3(4) MnsN(5)sC(10) 114.3(3)
N(3)sC(10)sN(5) 126.8(4)
1
(include CH2Cl2) requires C, 60.10; H, 6.93; N, 8.76%. H NMR
(CDCl3): δ 0.03∼0.51(m, 9 H, SiMe3), 0.97∼1.44 (m, 12 H,
CH(CH3)2), 2.5∼2.89 (m, 12 H, N(CH3)2), 3.03∼3.19 (m, 2 H,
CHMe2), 5.35 (s, 2 H, CH2Cl2), 7.01∼7.47 (m, 18 H, Ph). 13C NMR
(CDCl3): δ 1.52 (SiMe3), 24.5 (CH(CH3)2), 28.9 (CH(CH3)2), 39.0
(N(CH3)2), 54.4 (CH2Cl2), 123.5 (p-CAr), 124.1 (m-CAr), 133.7
(o-CAr), 129.4 (p-CPh-P), 130.7 (m-CPh-P), 134.9 (o-CPh-P), 142.0
(Cipso-Ph-P), 145.3 (Cipso-Ar), 145.8, 146.7 (NCN). 31P NMR
(CDCl3): δ -3.90.
3
FesN(1)
FesN(5)
FesN(6)
FesN(10)
N(1)sFesN(5)
C(1)sN(3)sC(4) 127.3(2) FesN(1)sC(1)
N(1)sC(1)sN(3) 129.3(2) FesN(5)sC(4)
N(3)sC(4)sN(5) 123.2(2)
2.014(2) N(1)sC(1)
2.038(2) N(3)sC(1)
2.018(2) N(3)sC(4)
2.031(2) N(5)sC(4)
94.57(8) N(6)sFesN(10)
1.344(3)
1.304(3)
1.346(3)
1.327(3)
94.16(8)
116.33(16)
118.20(16)
[N(Dipp)C(NMe2)NC(NMe2)N(H)]2Cu (7). (CH3)2NCN (0.35
mL, 4.30 mmol) was added to a solution of (Dipp)N(Li)SiMe3 (0.55
g, 2.15 mmol) in Et2O (30 cm3) at -78 °C. The resulting mixture
was warmed to ca. 25 °C and stirred for overnight. CuCl (0.11 g,
1.07 mmol) was added at -78 °C. The resulting mixture was
allowed to warm to ca. 25 °C and stirred for overnight. The volatiles
were removed in vacuo, and the residue was extracted with
dichloromethane and filtered. The filtrate was concentrated in vacuo
to ca. 10 cm3 and left at room temperature in air for 3 d, yielding
black crystals of 7 (0.32 g, 43%). Mp: 152∼154 °C. Found: C,
62.10; H, 8.83; N, 20.19. C36H60N10Cu requires C, 62.08; H, 8.68;
N, 20.11%.
X-ray Crystallography. Data collection of 1c, 1d, and 2-7 was
performed with Mo KR radiation (λ ) 0.71073 Å) on a Bruker
Smart Apex CCD diffractometer at 298(2) or 213(2) K. Crystals
were coated in oil and then directly mounted on the diffractometer
under a stream of cold nitrogen gas. A total of N reflections were
collected by using ω scan mode. Corrections were applied for
Lorentz and polarization effects as well as absorption using
multiscans (SADABS).24 The structure was solved by direct method
(SHELXS-97).25 Then the remaining non-hydrogen atoms were
obtained from the successive difference Fourier map. All non-
hydrogen atoms were refined with anisotropic displacement pa-
rameters, whereas the hydrogen atoms were constrained to parent
sites, using a riding mode (SHELXTL).26 Crystal data and details
of data collection and refinements for 1c, 1d, and 2-7 are
summarized in Table 1. Selected bond distances and bond angles
are listed in Table 2, Table 3, and Table 4.
4
CosN(1)
CosN(5)
CosN(6)
CosN(10)
N(1)sCosN(5)
C(1)sN(3)sC(4) 126.8(3) CosN(1)sC(1)
N(1)sC(1)sN(3) 126.3(3) CosN(5)sC(4)
N(3)sC(4)sN(5) 123.8(3)
1.996(2) N(1)sC(1)
1.989(2) N(3)sC(1)
1.990(2) N(3)sC(4)
1.991(2) N(5)sC(4)
95.94(10) N(6)sCosN(10)
1.330(4)
1.338(4)
1.327(4)
1.358(4)
96.26(10)
113.97(19)
118.40(19)
5
NisN(1)
NisN(5)
1.897(3) N(3)sC(10)
1.857(3) N(5)sC(10)
1.368(5) N(2)sC(7)
1.327(5) N(4)sC(10)
0.8600
1.341(5)
1.302(5)
1.336(5)
1.355(5)
N(1)sC(7)
N(3)sC(7)
N(5)s H(5A)
N(1)sNisN(5)
C(7)sN(3)sC(10) 118.8(3) NisN(1)sC(7)
N(1)sC(7)sN(3) 126.6(4) NisN(5)sC(10)
87.43(14) N(3)sC(10)sN(5) 123.9(4)
116.5(3)
125.2(3)
Table 4. Selected Bond Lengths (Angstroms) and Angles (Degrees) for
6 and 7
6
CusN(1)
CusN(5)
CusP
PsC(22)
PsC(28)
PsC(39)
N(1)sC(1)
N(1)sCusN(5)
N(1)sCusP
N(5)sCusP
C(22)sPsCu
C(13)sN(1)sCu
C(16)sN(5)sCu
C(13)sN(1)sC(1)
N(1)sC(13)sN(3)
1.984(3)
1.984(3)
2.164(9)
1.827(4)
1.833(4)
1.830(3)
1.420(4)
95.31(11)
136.94(8)
125.45(8)
105.95(11)
118.2(2)
112.2(2)
121.5(3)
125.7(3)
N(1)sC(13)
N(2)sC(13)
N(3)sC(13)
N(3)sC(16)
N(4)sC(16)
N(5)sC(16)
N(5)sSi
C(22)sPsC(28)
C(28)sPsC(39)
C(22)sPsC(39)
C(28)sPsCu
C(39)sPsCu
C(13)sN(3)sC(16)
N(3)sC(16)sN(5)
C(16)sN(5)sSi
1.327(4)
1.393(4)
1.342(4)
1.325(4)
1.377(4)
1.342(4)
1.710(3)
102.21(16)
101.20(16)
104.54(16)
119.72(11)
120.89(12)
126.5(3)
127.7(3)
126.9(2)
Results and Discussion
Synthesis and Characterization. The starting material for
the synthesis of the new metal complexes was ArN(SiMe3)Li
(Ar ) Ph or Dipp).21,22,27 Treatment with ButONa in hexane
yielded the hexane-insoluble ArN(SiMe3)Na.28 The above
lithium and sodium salts were the source of the crystal-
7
Cu(1)sN(1)
Cu(1)sN(4)
N(1)sC(1)
N(3)sC(1)
N(1)sCu(1)sN(4)
C(1)sN(3)sC(4)
N(1)sC(1)sN(3)
2.008(2)
1.914(2)
1.336(3)
1.319(4)
89.54(10)
124.2(2)
128.1(3)
N(3)sC(4)
N(4)sC(4)
N(2)sC(1)
N(5)sC(4)
N(3)sC(4)sN(4)
Cu(1)sN(1)sC(1)
Cu(1) sN(4)sC(4)
1.340(4)
1.308(4)
1.414(4)
1.371(4)
125.7(2)
123.4(19)
129.0(2)
(24) Sheldrick, G. M. Correction Software; University of Go¨ttingen:
Go¨ttingen, Germany, 1996.
(25) Sheldrick, G. M. Program for the Solution of Crystal Structures;
University of Go¨ttingen: Go¨ttingen, Germany, 1997.
(26) Program for Crystal Structure Refinement; Bruker Analytical X-ray
Instruments Inc.: Madison, WI, USA, 1998.
123.8 (p-CPh), 127.6 (m-CPh), 130.0 (o-CPh), 141(Cipso), 155.0,
158.8 (NCN).
[N(Dipp)C(NMe2)NC(NMe2)N(SiMe3)]CuPPh3 (6). (CH3)2-
NCN (0.40 mL, 5.02 mmol) was added to a solution of (Dipp)N-
(27) Bezombes, J.-P.; Hitchcock, P. B.; Lappert, M. F.; Merle, P. G.
J. Chem. Soc., Dalton Trans. 2001, 816–821.
(28) Antolini, F.; Hitchcock, P. B.; Lappert, M. F.; Merle, P. G. Chem.
Commun. 2000, 1301–1302.
Inorganic Chemistry, Vol. 47, No. 15, 2008 6695

Zhou et al.
Scheme 1. Synthetic Routes to 1-7
line 1,3,5-triazapentadienate 1a-1c or complexes of man-
ganese 2, iron 3, cobalt 4, nickel 5, copper(I) 6, and
copper(II) 7. The synthetic routes to 1-7 were illustrated in
Scheme 1.
Treatment of (Dipp)N(Li)SiMe3 with 2 equiv of
(CH3)2NCN in diethyl ether and recrystallization from Et2O
gave 1c as colorless crystals in 60% yield. 1d was obtained
by careful hydrolysis of 1c via addition of diluted distilled
water in Et2O at ambient temperature. 1a and 1b were not
isolated but were generated in situ in a similar procedure to
that for 1c.
Treatment of 1a with anhydrous manganese dichloride in
diethyl ether and recrystallization from dichloromethane gave
2 as colorless crystals in 42% yield. 3 and 4 were obtained
in good yields via the reaction of 1b with anhydrous FeCl2
or CoCl2 as brown-yellow and purple crystals, respectively.
They were slightly air and moisture sensitive in the solvent
Figure 3. Molecular structure and atom numbering scheme for 2.
Figure 1. Molecular structure and atom numbering scheme for 1c.
Figure 2. Molecular structure and atom numbering scheme for 1d.
6696 Inorganic Chemistry, Vol. 47, No. 15, 2008
Figure 4. Molecular structure and atom numbering scheme for 3.

Synthesis and Structures of Selected Triazapentadienate
Figure 5. Molecular structure and atom numbering scheme for 4.
Figure 8. Molecular structure and atom numbering scheme for 7.
1c, 1d, and 2-7 were characterized by microanalysis and
X-ray single-crystal diffraction, and 1c, 1d, 5, 6 by NMR
spectra at ambient temperature. 2, 3, 4, and 7 were
1
paramagnetic as demonstrated by broad peaks in their H
1
NMR spectra. The H NMR and 13C NMR spectra of 1c,
7
1d, 5, and 6 were normal. The Li NMR spectrum of 1c
displayed two signals at δ 2.05 and 2.36 due to two different
lithium environments, consistent with the solid-state structure.
The 31P NMR spectrum of 6 in CDCl3 showed a broad singlet
at δ -3.90 without Cu-P coupling. The microanalysis data
of 1c, 1d, and 2-7 were in agreement with the structures
we obtained from the X-ray crystallography.
Crystal Structures. Structure of 1c. The molecular
structure of crystalline 1c is illustrated in Figure 1. 1c is a
head-to-head dimer built around a planar LiNLiN ring; the
angles at the nitrogen atoms are narrower [79.5(3), 79.5(3)°]
than those at the lithium atoms [100.1(3), 100.9(3)°]. Each
lithium atom is coordinated with four nitrogen atoms from
two ligands. Each ligand NCNCN backbone adopts a twisted
W-shaped conformation. The dihedral angles between the
two LiNCN moieties linked by N3 and Li1 are 44.5 and
46.1°, respectively. The molecule 1c has two fused back-
to-back tricyclic boat motifs comprising a central plane
N3Li1N8Li2 (mean deviation 0.0043 Å) ring flanked by
planesN3Li1N1C2(meandeviation0.0633Å)andN8C9N10Li2
(mean deviation 0.0092 Å), N6Li1N8C3 and N3Li2N5C4,
respectively. The dihedral angle between the core N3Li1N8Li2
and the adjacent four-membered rings N1C2N3Li1 or
N8C9N10Li2 are 33.5 and 34.2 °. The bond distances
N1-C2, C2-N3, N3-C4, and C4-N5 are 1314(5), 1.370(5),
1.374(5), and 1.304(5) Å, respectively, indicating an obvious
short-long-long-short pattern of C-N bond lengths in the
NCNCN backbone. This is consistent with localized CdN
and C-N bonding in previously reported monomeric U-
shaped lithium 1,3,5-triazapentadienyl adducts of fluorinated
ligands [{N{(C3F7)C(Dipp)N}2}Li(THF)] and [{N{(C3F7)-
C(Mes)N}2}Li(THF)2],11 also in dimeric W-shaped 1,3,5-
triazapentadienyl ligand [RNC(NMe2)NC(NMe2)NR]- (R )
SiMe3).23 The C-N bond distances in NCNCN backbone
of 1c are slightly longer than those in [RNC(NMe2)NC(NMe2)-
NR]- (R ) SiMe3)23 and comparable to C(sp2)dN(sp2) [1.28
Å ] and C(sp2)-N(sp2) [1.37 Å] bond distances in tri- and
tetraaza-heptatrienyllithium compounds.20 The delocalized
Figure 6. Molecular structure and atom numbering scheme for 5.
Figure 7. Molecular structure and atom numbering scheme for 6.
and relatively stable in the solid state for a couple of hours,
very soluble in Et2O. A similar methodology to 3 and 4 was
used in the reaction of 1b and NiCl2 ·6H2O gave red crystals
of nickel 5. Because of the d8 configuration, nickel preferred
a planar geometry and trimethylsilyl groups were inevitably
hydrolyzed. 6 was obtained via the reaction of 1c with
anhydrous CuCl /PPh3, and colorless suitable single crystals
of 6 for X-ray analysis were obtained by recrystallization in
dichloromethane in situ. Black crystals of 7 were obtained
via the reaction of 1c with anhydrous CuCl and recrystal-
lization in dichloromethane in air via oxidation of Cu(I) and
hydrolysis of SiMe3.
Inorganic Chemistry, Vol. 47, No. 15, 2008 6697

Zhou et al.
Table 5. Selected Structural Data for Complexes 2-7a
a γ: Dihedral angle between two NMN planes of 2-7.
guanidinato system is impaired although the smaller dihedral
angles exist between N1C2N3Li1 and C23N2C24 (24.5 °)
or N3C4N5Li2 and C29N4C32 (19.8 °). This is also found
in the other ligand NCNCN moiety of the molecule.
roughly in the range for C(sp2)-N(sp2) bonds (ca. 1.36 Å).30
The dihedral angle between N(1)-C(13)-N(3) and C(14)-
N(2)-C(15) planes is 33.7°; and between N(3)-C(16)-N(4)
and C(17)-N(5)-C(18) planes is 11.2°. They are much
smaller than those guanidinato moieties found in
[{iPrNC[N(SiMe3)2]NiPr}2ZrCl2] [88.2°], [{CyNC[N-
(SiMe3)2]NCy}2ZrCl2] [86.3°], or [{CyNC[N(SiMe3)2]-
NCy}2HfCl2] [85.8°]31 and in [PhNC(NMe2)NSiMe3]3ZrCl3
[40.3°] or [PhNC(NMe2)NSiMe3]3HfCl3 [39.8° ],21,22 indi-
cating the π conjugation to some extent between the NCN
and NMe2 moieties.
The terminal N(1)-C(1) bond distance is 1.416(2) Å,
comparable to the 1.402 (2) Å C-N distance in aniline.32
The phenyl and N1-C13-N3 planes are almost perpen-
dicular with dihedral angle of 86.7°. It is of an arrangement
that minimizes steric strain.
Structure of 1d. The molecular structure of crystalline
1d is illustrated in Figure 2. For the NCNCN moiety, a
short-long-short-long pattern of C-N bond lengths can
be seen: d(N(1)-C(13)) and d(N(3)-C(16)) are 1.288(2) and
1.311(3) Å, respectively, while d(C(13)-N(3)) and
d(C(16)-N(4)) are 1.379(3) and 1.360(3) Å, respectively.
The short bonds correspond to CdN fragments and the long
bonds to C-N moieties, indicating some CdN characteristics
of conjugated system in 1d. However, in the molecule, the
N3C2 framework is not coplanar. It has instead a distinct
helical twist such that the dihedral angle between the
N(1)-C(13)-N(3) and N(3)-C(16)-N(4) planes is 56.1°.
Therefore, this framework can be described as a somewhat
W-shaped or a twisted zigzag (S-shaped) conformation. The
bondanglesofN1-C13-N3andN3-C16-N4are124.03(17)
and 124.38(19)°, respectively. By comparison, a similar C-N
bond distance trend is found for the neutral 1,3,5-triazap-
entadienyl adducts of fluorinated ligands such as W-shaped
[N{(C3F7)C(Dipp)N}2]H,7 [N{(C3F7)C(Mes)N}2]H (where
Structures of 2, 3, and 4. The crystalline triazapentadi-
enato-manganese 2, -iron 3, and -cobalt 4 complexes are
monomeric and have a similar geometry.
In the crystal structure of 2 (Figure 3), the central metal
manganese is located in a tetrahedral environment defined
by the four nitrogen atoms from the two bidentate 1,3,5-
triazapentadieno
ligands
[PhNC(NMe2)NC(NMe2)N-
Mes
)
2,4,6-trimethylphenyl),11
and
U-shaped
(SiMe3)]-, with Mn-N bond distances of 2.096 (4) [Mn-N1],
2.076 (4) [Mn-N5], 2.074 (4) [Mn-N6] and 2.103 (4) Å
[Mn-N10], respectively. The bond angles N1-Mn-N5 and
N6-Mn-N10 are 92.85 (15) and 93.02 (15) °, respectively.
The dihedral angle between N1MnN5 and N6MnN10 is
90.2 °. Within the 1,3,5-triazapentadieno ligand, the N1-C7
[N{(C3F7)C(Ph)N}2]H.2 This is also observed in the neutral
ꢀ-diketiminato ligand [HC{(C3F7)C(Dipp)N}2]H.29
For the guanidinato moiety C13N3, although the C-N
bond lengths are in the wider range of 1.288(2)∼1.388(2)
Å, whereas 1.388 Å was considered to correspond to short
single bond; and for the other (C16N3), the C-N bond
lengths are in the range of 1.311(3)∼1.360(3) Å, they are
(30) Allen, F. H.; Kennard, O.; Watson, D. G.; Brammer, L.; Orpen, A. G.
; Taylor, R. J. Chem. Soc., Perkin Trans. 1987, 2, S1.
(31) Wood, D.; Yap, G. P. A.; Richeson, D. S. Inorg. Chem. 1999, 38,
5788–5794.
(29) Carey, D. T.; Cope-Eatough, E. K.; Vilaplana-Mafe, E.; Mair, F. S.;
Pritchard, R. G.; Warren, J. E.; Woods, R. J. Dalton Trans. 2003,
1083–1093.
(32) Lister, D. G.; Tyler, J. K.; Hog, J. H.; Larsen, N. W. J. Mol. Struct.
1974, 23, 253–264.
6698 Inorganic Chemistry, Vol. 47, No. 15, 2008

Synthesis and Structures of Selected Triazapentadienate
[1.343(6) Å], C7-N3 [1.324 (5) Å], N3-C10 [1.328 (5)
Å], C10-N5 [1.335 (5) Å] distances are very similar. Bond
angles N1-C7-N3, C7-N3-C10 and N3-C10-N5 are
125.3(4), 127.3(4) and 126.8(4)°, respectively. Each bidentate
1,3,5-triazapentadieno ligand forms a six-membered metal-
lacycle MNCNCN, where the N1C7C10N5 four-membered
ring is almost planar with a mean deviation of 0.18 Å. The
dihedral angle between the N1C7C10N5 and the N1MnN5
is 7.7°. The dihedral angle between planes N1C7C10N5 and
C7N3C10 is 7.7° as well. The dihedral angle formed by the
planar NMe2 function and its adjacent CsNsC plane is 15°.
For both 3 (Figure 4) and 4 (Figure 5), the central metal
iron and cobalt are located in a tetrahedral environment
defined by the four nitrogen atoms from the two bidentate
1,3,5-triazapentadieno ligands, the dihedral angle between
N1MN5 and N6MN10 being 88.6° (3) and 90.1° (4),
respectively. In 3, the Fe-N bond distances are in the range
of 2.014 (2)∼2.038 (2) Å, shorter than the corresponding
values found for manganese complex 2 [Mn-N: 2.074-
(4)∼2.103(4) Å] and longer than the Co-N bond distances
in complex 4 [Co-N: 1.989(2)∼1.996(2) Å]. The bond
angles N1-Fe-N5 and N6-Fe-N10 in 3 are 94.57(8) and
94.16(8)°, respectively. They are larger than those in 2
[92.85(15) and 93.02(15)] and smaller than those in 4
[95.94(10) and 96.26(10)]. In the ligand moiety NCNCN,
theC-Nbonddistancesareintherangeof1.304(3)∼1.346(3)Å
in 3, and 1.327(4)∼1.358 (4) Å in 4. The bond angles of
N1-C1-N3, C1-N3-C4, and N3-C4-N5 are 129.3(2),
127.3 (2), and 123.2 (2)°, respectively, in 3, and those in 4
are 126.3(3), 126.8(3), and 123.8(3)°, respectively.
For the CN3 framework in 3, the three C-N bond distances
in the guanidinate ligand are N1-C1 1.344(3) Å, N2-C1
1.424(3) Å, and N3-C1 1.304(3) Å, respectively. All of
these bond distances are roughly in the range for
C(sp2)-N(sp2) bonds. This is also found in 2 and 4 and is
an indication of lone pair donation from the nitrogen atom
(dimethylamido group) to the central carbon and concomitant
electron delocalization involving all three nitrogen atoms of
the chelating ligand.
Structure of 5. The centrosymmetric 5 (Figure 6) has a
planar geometry different from 2, 3, and 4 because of the
loss of the two trimethylsilyl groups. The bond distances
Ni-N1 and Ni-N5 are 1.897(3) and 1.857(3) Å, respec-
tively. The bond angle N1-Ni-N5 is 87.43(14)°. It is noted
that dihedral angle between planes N1C7N5 and N1C10N5
is 10.6°, and thus atoms N1, C7, C10, and N5 can be
regarded in a plane (mean deviation 0.06 Å). However,
dihedralanglesbetweenN1NiN5orC7N3C10andN1C7C10N5
are 34.6 and 15.4°, respectively. That means the N3 and
nickel atoms actually are out the planes (average vertical
distance from nickel and N3 to the plane NC-CN are ca.
0.76 and 0.17 Å, respectively). For the ligand NCNCN
moiety, the C-N bond distances are in the range of
1.302(5)∼1.368(5) Å. The bond angles N1-C7-N3,
C7-N3-C10, and N3-C10-N5 are 126.6(4), 118.8(3), and
123.9(4)°, respectively. The dihedral angle between N1C7N3
and C8N2C9 is 15.4°. Two reasonably close analogues are
the ꢀ-diketiminate:
having Ni-N bond distances of 1.845(3) and 1.855(3) Å,5
and [Ni{NHdC(Py)NdC(Py)NH}2] (Py ) 4-pyridyl; 3-py-
ridyl) having the Ni-Nsp2 distances of 1.847(2), 1.855 (2)
Å and 1.876(3) and 1.856(3) Å.16
Structure of 6. The X-ray crystal structure of 6 (Figure
7) reveals the presence of a three-coordinate, trigonal-planar
copper center. The triazapentadienyl ligand acts as a κ2-
donor. The Cu-N bond distances are both 1.984(3) Å. The
four atoms N1, C13, C16, and N5 are essentially planar with
a deviation of 0.11 Å, and the dihedral angle between
N1C13C16N5 and C13N3C16 is 10.3°. The dihedral angle
between N1C13C16N5 and N1CuN5 is 25.2°. The bond
angle of N1-Cu-N5 is 95.31(11)°. In the NCNCN moiety,
the C-N bond distances are in the range of 1.325(4)∼1.342(4)
Å, indicating the NCNCN fragment has π-electron delocal-
izationpresentasaη5 anion.ThebondanglesofN1-C13-N3,
C13-N3-C16, and N3-C16-N5 are 125.7(3), 126.5(3),
and 127.7(3)°, respectively. The Dipp group is twisted by
about 71.9° from the CuN1C13 plane. The Cu-P bond
distance in 6 is 2.164(9) Å, similar to 2.166 (8) Å in the
three-coordinate Cu(I) ꢀ-diketiminate complex containing
triphenylphosphine.33
Structure of 7. In 7 (Figure 8), the dihedral angle between
N1Cu1N4andN1′Cu1N4′is38.7°;bothanglesofN1-Cu1-N4
and N1′-Cu1-N4′ are 89.54(10) °; N1-Cu1-N1′ and
N4-Cu1-N4′ are 154.18(13) and 151.94(16)°, respectively.
So the central metal copper is located in a marked distorted
tetrahedral geometry environment and bonded by four
nitrogen atoms from two ligands. The bond distances
Cu1-N1 and Cu1-N4 are 2.008(2) and 1.914(2) Å,
respectively. The four atoms N1, C1, C4, and N4 are almost
in the same plane (mean deviation 0.0039 Å). The dihedral
angle between N1C1C4N4 and N1Cu1N4 is 2.9°, and
between N1C1C4N4 and C1N3C4 is 2.2°, respectively.
Therefore, each of the six-membered metallacycles is
regarded coplanar, giving a π-electron delocalized system.
The dihedral angle [48.9 °] between plane C2N2C3 from
guanidinato function NMe2 and its adjacent plane N1C1N3
suggests the strong π-bonding interaction between the two
moieties. For the CN3 framework in 7, the three C-N bond
distances in the guanidinate part are N1-C1 1.336(3), N2-C1
1.414(4), and N3-C1 1.319(4) Å, respectively. All of these
data indicate the lone-pair donation from the nitrogen atom
(dimethylamido group) to the central carbon C1 and concomi-
tant electron delocalization involving all three nitrogen atoms
of the guanidinato chelating ligand.
Table 5 provides a summary of some important geometric
data (bond lengths in Å and angles in degrees) for 2-7. For
2-5, bond lengths M-N(Ar) and M-N(R) decrease in the
sequence 2 > 3 > 4 > 5 and for a certain complex of 2, 3,
5 and 7, M-N(Ar) > M-N(R). The mean C-N bond
lengths in 2-7 are comparable and accord with the
C(sp2)-N(sp2) bond lengths. Bond angles of N-M-N in 5
[87.43(14)°], 7 [89.54(10)°] and C-N-C in 5 [118.8(3)°]
(33) York, J. T.; Young, V. G.; Tolman, W. B. Inorg. Chem. 2006, 45,
4191–4198.
Inorganic Chemistry, Vol. 47, No. 15, 2008 6699

Zhou et al.
are relatively smaller than those in other complexes [from
92.85(15) to 95.94(10)° for 2-4 and 6]. In 2 and 4, the metal
is located in a nearly rigorously tetrahedral coordination
environment with 90.2 and 90.1° of dihedral angles between
two NMN planes. 5 adopts a square-planar geometry because
of the d8 configuration of nickel atom, 3 and 7 adopt distorted
tetrahedral (trigonal planar for 6) although 3 has a tendency
to give a nearly rigorously tetrahedral and 7 toward a square
planar configuration.
copper complexes 6 and 7 as precursors of atomic layer
deposition or magnetic materials in microelectronics.35
Further studies on the coordination chemistry of this interest-
ing class of triazapentadienato ligands with guanidinato
moieties and the application of their metal complexes are
presently underway.
Acknowledgment. We thank the Natural Science Founda-
tion of China (grants 20672070 and 20772074) and Shanxi
(2007011020), the Foundation for Returned Overseas Chi-
nese Scholars of Shanxi Province (2006, M. Zhou), Shanxi
Key Laboratory Foundation for Functional Molecules (Grant
20053002).
Conclusions
In this study, we have isolated a series of new 2,4-
dimethylamido substituted 1,3,5-triazapentadienato ligands
and metal complexes by the reaction of PhN(SiMe3)M (M
) Li or Na) or (Dipp)N(SiMe3)Li with 2 equiv of R-hydrogen-
free dimethylcyanamide, which led to in situ synthesis of
functional 1,3,5-triazapentadienato complexes with guanidi-
nato moieties. The NCNCN backbone adopts either W- or
U-shaped conformation. Compounds such as 3, 4, and 5 may
serve as potential catalysts in olefin polymerization34 and
Supporting Information Available: X-ray crystallographic files
in CIF format for the structure determinations of the eight
compounds in Table 1. This material is available free of charge
via the Internet at http://pubs.acs.org.
IC800320E
(34) (a) Jayaratne, K. C.; Sita, L. R. J. Am. Chem. Soc. 2000, 122, 958–
959. (b) Littke, A.; Sleiman, N.; Bensimon, C.; Richeson, D. S.; Yap,
G. P. A.; Brown, S. J. Organometallics 1998, 17, 446–451. (c) Li,
J.-F.; Song, H.-B.; Cui, C.-M.; Cheng, J.-P. Inorg. Chem. 2008, 47,
3468–3470.
(35) (a) Li, Z.; Barry, S. T.; Gordon, R. G. Inorg. Chem. 2005, 44, 1728–
1735. (b) Sadique, A. R.; Heeg, M. J.; Winter, C. H. Inorg. Chem.
2001, 40, 6349–6355.
6700 Inorganic Chemistry, Vol. 47, No. 15, 2008