Synthesis of Bis(phosphine) and N-heterocyclic carbene supported α- Diazoalkyl complexes of copper(I)

Article abstract of DOI:10.1021/om900566k

(2, 6-Dimesitylphenyl)diazomethane, N₂CH(dmp) (1; dmp = 2,6-(2,4,6-Me₃C₆H₂)₂C ₆H₃), undergoes deprotonation by LiN(i-Pr)₂ to give [N₂C(dmp)][Li] (2), which

Full text of DOI:10.1021/om900566k

Organometallics 2009, 28, 6135–6138 6135
DOI: 10.1021/om900566k
Synthesis of Bis(phosphine) and N-Heterocyclic Carbene Supported
r- Diazoalkyl Complexes of Copper(I)
Vlad M. Iluc, Carl A. Laskowski, and Gregory L. Hillhouse*
Department of Chemistry, Gordon Center for Integrative Science, The University of Chicago, 929 E. 57th
Street, Chicago, Illinois 60637
Received July 1, 2009
Summary: (2,6-Dimesitylphenyl)diazomethane, N2CH(dmp)
(1; dmp = 2,6-(2,4,6-Me3C6H2)2C6H3), undergoes deprotona-
tion by LiN(i-Pr)2 to give [N2C(dmp)][Li] (2), which reacts with
diethyl ether solutions of {(dtbpe)Cu(μ-Cl)}2 (3; dtbpe = 1,2-
bis(di-tert-butylphosphino)ethane) or (IPr)Cu(Cl) (4; IPr = 1,3-
bis(2,6-diisopropylphenyl)imidazolin-2-ylidene) to generate the
metathesis products (L)Cu-C(N2)dmp (5, L = dtbpe; 6, L =
IPr) as diamagnetic yellow crystalline solids in 80% and 82%
yields, respectively. Reaction of 1 with n-BuLi results in addition
of n-Bu- to the terminal nitrogen of 1 to generate a hydrazonyl
anion that reacts with 3 to afford the hydrazonyl complex
(dtbpe)Cu-N(n-Bu)NdCH(dmp) (7) in 75% yield. Complexes
5-7 have been characterized by spectroscopic (NMR, IR) and
X-ray diffraction methods.
carbyne trapping or rearrangement has been observed.3
Herein we report the synthesis and structural characteriza-
tion of Cu(I) diazoalkyls containing trialkylphosphine and
N-heterocyclic carbene ancillary ligands and a bulky terphe-
nyl substituent on the diazenyl carbon.
Results and Discussion
For these studies we sought a crystalline, bulky monosub-
stituted diazoalkane to facilitate synthetic manipulations
and offer steric stabilization. (2,6-Dimesitylphenyl)diazo-
methane, N2CH(dmp) (1; dmp = 2,6-(2,4,6-Me3C6H2)2C6H3),
was prepared in three steps from 2,6-dimesitylphenyl iodide,
(dmp)I,4 in 54% overall yield. The preparation followed stan-
dard synthetic protocols, except that longer reaction times and
higher temperatures were required compared with the reaction
conditions for smaller aryl derivatives (e.g., N2CHPh).5 Fol-
lowing a procedure for a related compound,6 monolithiation of
(dmp)Iincyclohexane4b followed by addition of N,N-dimethyl-
formamide allowed for the isolation of (dmp)CHdO in 70%
yield. Hydrazine condensation with the aldehyde gave (dmp)-
CHdN2H2 (93% yield), and oxidation of the hydrazone with
an excess of HgO gave 1 as a light salmon colored solid in
82% yield. The IR spectrum of 1 shows νNN 2052 cm-1 and
νCN 1374 cm-1. No photosensitivity was observed on pro-
longed exposure of a C6D6 solution of 1 (NMR tube) to
ambient light, and this is likely correlated to its weak absorption
in the visible region.
Reaction of 1 with 1 equiv of LiN(i-Pr)2 (LDA) results in
deprotonation to form [N2C(dmp)][Li] (2; Scheme 1), which
was not isolated but was used in situ. Addition of solutions of
2 to ether solutions of {(dtbpe)Cu(μ-Cl)}2 (3; dtbpe = 1,2-bis-
(di-tert-butylphosphino)ethane)7 or (IPr)Cu(Cl) (4; IPr =
1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene)8 generates
the diazoalkyls (L)Cu-C(N2)dmp (5, L = dtbpe; 6, L = IPr)
as diamagnetic yellow crystalline solids in 80% and 82% yields,
respectively (Scheme 1; Figures 1 and 2). The NMR spectra of 5
and 6 exhibit C2v pseudosymmetric environments, indicating
free rotation around the Cu-C bonds in both complexes.
Attempts to induce N2 elimination, either thermally or photo-
chemically, led to decomposition and intractable products.
Interest in the coordination chemistry of diazoalkanes
(N2CRR0) has been fueled by their use as synthons for
carbene complexes (LnMdCR2) upon N2 loss, in stoichio-
metric and catalytic carbene-transfer processes.1 Often,
however, these energy-rich molecules form stable coordina-
tion complexes that are impervious to dinitrogen elimina-
tion.2 While no comparable reagents of general utility for the
direct installation of carbyne ligands (LnMtCR) have been
developed, it is noteworthy that monosubstituted diazoalk-
anes (N2CHR) can be deprotonated to give the lithiated
anionic derivatives [N2CR][Li], which in turn have been used
in salt metathesis reactions to prepare R-diazoalkyl com-
plexes of Co, Rh, Os, Ni, Pd, and Pt (i.e., LnM-C(N2)R).3
These complexes have not yet been successfully converted to
stable carbyne species, but N2 elimination with subsequent
*To whom correspondence should be addressed. E-mail: g-hillhouse@
uchicago.edu.
(1) (a) Moser, W. R. J. Am. Chem. Soc. 1969, 91, 1135. (b) Nozaki, H.;
Moriuti, S.; Yamabe, M.; Noyori, R. Tetrahedron Lett. 1966, 59. (c) Nozaki,
H.; Moriuti, S.; Takaya, H.; Noyori, R. Tetrahedron Lett. 1966, 5239.
(d) Corey, E. J.; Myers, A. G. Tetrahedron Lett. 1984, 25, 3559.
(e) Salomon, R. G.; Kochi, J. K. J. Am. Chem. Soc. 1973, 95, 3300.
(f) Salomon, R. G.; Kochi, J. K. J. Chem. Soc., Chem. Commun. 1972, 559.
(g) Herrmann, W. A.; Hubbard, J. L.; Bernal, I.; Korp, J. D.; Haymore, B. L.;
Hillhouse, G. L. Inorg. Chem. 1984, 23, 2978. (h) Mindiola, D. J.; Hillhouse,
G. L. J. Am. Chem. Soc. 2002, 124, 9976. (i) Doyle, M. P. Chem. Rev. 1986,
86, 919.
(2) Hillhouse, G. L.; Haymore, B. L. J. Am. Chem. Soc. 1982, 104,
1537 and references therein.
(3) (a) Deydier, E.; Menu, M. J.; Dartiguenave, M.; Dartinguenave,
Y.; Simard, M.; Beauchamp, A. L.; Brewer, J. C.; Gray, H. B. Organo-
metallics 1996, 15, 1166. (b) Koenig, H.; Menu, M. J.; Dartiguenave, M.;
Dartinguenave, Y.; Klien, H. L. J. Am. Chem. Soc. 1990, 112, 5351.
(c) Murahashi, S.; Kitani, Y.; Uno, T.; Kunio, H.; Tadashi, M.; Kasai, N.
Organometallics 1986, 5, 356. (d) Gallop, M. A.; Jones, T. C.; Richard, E. F.;
Roper, W. R. J. Chem. Soc., Chem. Commun. 1984, 1002. (e) Menu, M. J.;
Desrosiers, P.; Dartiguenave, M.; Dartiguenave, Y.; Bertrand, G. Organo-
metallics 1987, 6, 1822.
(4) (a) Du, C. F.; Hart, H.; Ng, K. D. J. Org. Chem. 1986, 51, 3162.
(b) Gavenonis, J.; Tilley, T. D. J. Am. Chem. Soc. 2002, 124, 8536.
(5) Staudinger, H.; Gaule, A. Chem. Ber. 1916, 49, 1897.
(6) Luning, U.; Baumgartner, H.; Manthey, C.; Meynhardt, B.
J. Org. Chem. 1996, 61, 7922.
(7) Blue, E. D.; Davis, A.; Conner, D.; Gunnoe, T. B.; Boyle, P. D.;
White, P. S. J. Am. Chem. Soc. 2003, 125, 9435.
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2417.
r
2009 American Chemical Society
Published on Web 09/23/2009
pubs.acs.org/Organometallics

6136 Organometallics, Vol. 28, No. 20, 2009
Iluc et al.
Figure 2. Molecular structure of 6 drawn with 35% probability
ellipsoids. H atoms are omitted for clarity. Selected metrical para-
meters: Cu(1)-C(4) = 1.896(2), C(4)-N(4) = 1.305(3), N(4)-
Figure 1. Molecular structure of 5 drawn with 35% probability
ellipsoids. H atoms are omitted for clarity. Selected metrical para-
meters: Cu-C = 1.963(2), C-N(1) = 1.286(2), N(1)-N(2) =
˚
N(5) = 1.155(2), C(4)-C(31) = 1.476(3) A; C(4)-N(4)-N(5) =
˚
1.151(2), C-C(31) = 1.494(2) A; Cu-C-C(31) = 134.75(12),
175.0(2), C(1)-Cu(1)-C(4) = 163.47(9), Cu(1)-C(4)-C(31) =
129.3(2), Cu(1)-C(4)-N(4) = 114.1(2), C(31)-C(4)-N(4) =
116.4(2)°.
Cu-C-N(1) = 112.98(12), C(31)-C-N(1) = 111.88(14), C-
N(1)-N(2) = 177.41(2), P(1)-Cu-P(2) = 91.76(2), P(1)-Cu-C
= 151.40(5), P(2)-Cu-C = 116.43(5)°.
Scheme 1. Synthesis of dtbpe (5) and IPr (6) Supported Cu(I)
R-Diazoalkyl and Hydrazonyl (7) Complexes (Mes = 2,4,6-
Trimethylphenyl)
Figure 3. Molecular structure of one of two conformers of 7drawn
with 35% probability ellipsoids. H atoms (except on C(1)) are
omitted for clarity. Selected metrical parameters: Cu(1)-N(1) =
1.918(3), N(1)-N(2) = 1.337(4), N(2)-C(2) = 1.292(5), N(1)-
˚
Initial attempts to generate 2 utilized n-BuLi as a “deproto-
nating” agent, but interestingly n-BuLi acts rather as a nucleo-
phile, adding to the terminal nitrogen of N2CH(dmp) to
generate a hydrazonyl anion that on reaction with 3 gives the
diamagnetic hydrazonyl complex (dtbpe)Cu-N(n-Bu)NdCH-
(dmp) (7) in 75% isolated yield (Scheme 1; Figure 3).
C(1) = 1.465(5) A; Cu(1)-N(1)-C(1) = 120.5(2), C(1)-N(1)-
N(2) = 110.8(3), Cu(1)-N(1)-N(2) = 128.7(2)°.
the diazoalkane functionality (Figures 1 and 2). Structures of
previously reported transition-metal diazoalkyls show simi-
3
˚
˚
lar N-N (∼1.14 A) and C-N (∼1.29 A) values. The Cu-C
˚
Single-crystal X-ray diffraction studies of 5 and 6 reveal
structures with similar metrical parameters for the R-dia-
zoalkyl ligands, including short N-N (1.151(2) and 1.155(2)
bond distances (1.963(2), 1.896(2) A) are typical of those
found for other Cu(I) alkyls,9 with that in 5 being slightly
elongated with respect to 6 probably for steric reasons.
Copper exhibits planar coordination in 5, with steric inter-
actions leading to a distinct distortion from a Y-shaped
geometry (P-Cu-C = 151.40(5), 116.43(5)°) in the solid
state.
˚
A, respectively) and C-N bond distances (1.286(2) and
˚
1.305(3) A, respectively) consistent with the preservation of
(9) (a) Hope, H.; Olmstead, M. M.; Power, P. P.; Sandell, J.; Xu, X.
J. Am. Chem. Soc. 1985, 107, 4337. (b) Coan, P. S.; Folting, K.; Huffman,
J. C.; Caulton, K. G. Organometallics 1989, 8, 2724. (c) Dempsey, D. F.;
Girolami, G. S. Organometallics 1988, 7, 1208. (d) Mankad, N. P.; Gray,
T. G.; Laitar, D. S.; Sadighi, J. P. Organometallics 2004, 23, 1191.
Structural characterization of 7 reveals two independent
molecules within the unit cell differing in the conformation of
the n-Bu substituent (Figure 3; only one conformation

Note
Organometallics, Vol. 28, No. 20, 2009 6137
shown). The hydrazonyl ligand is planar. Although it is not
crystallographically required, C(1), N(11), N(12), C(151), and
the central aryl ring are coplanar due to extended conjugation.
and the mixture was stirred at room temperature for another 2 h.
The solvent was removed under reduced pressure, the solids
were extracted with 20 mL of n-pentane, and the filtrate was
cooled to -35 °C followed by filtration to give orange-
˚
The Cu(1)-N(11) bond, at 1.918(3) A, is somewhat longer
1
than in previously characterized copper amides.7,10 The geo-
metry of the metal center is trigonal planar, and with the steric
pressure of the terphenyl moiety ameliorated in 7 relative to 5,
the complex adopts a traditional Y-shaped structure.
pink crystals of 1 (0.82 g, 2.31 mmol, 82%). H NMR (20 °C,
500.13 MHz, C6D6): δ 6.96 (t, C6H3, 1H, JHH = 7.5 Hz), 6.88 (d,
C6H3, 2H, JHH = 7.5 Hz), 6.84 (s, C6H2, 4H), 4.04 (s, CHdN,
1H), 2.20 (s, CH3, 6H), 2.07 (s, CH3, 12H). 13C{1H} NMR
(20 °C, 125.77 MHz, C6D6): δ 137.41 (s, CAr), 137.36 (s, CAr),
136.64 (s, CAr), 135.56 (s, CAr), 129.16 (s, CAr), 128.43 (s, CAr),
127.57 (s, CAr), 124.49 (s, CAr), 44.08 (s, CHdN), 21.24 (s, CH3),
20.95 (s, CH3). IR (CaF2, Fluorolube): 3065 (w), 2969 (w), 2914
(w), 2854 (w), 2052 (s, νNdN), 1611 (w), 1437 (m, νCdN), 1374 (w)
cm-1. GC MS (m/z): 354 (Mþ), 326.
Experimental Section
Unless stated otherwise, all operations were performed in an
MBraun LabMaster drybox under an atmosphere of purified
nitrogen. Anhydrous diethyl ether was purchased from Fisher,
stirred over sodium metal, and filtered through activated alu-
mina. n-Pentane was purchased from Sigma Aldrich and dried
by passage through activated alumina and Q-5 columns. C6D6
was purchased from Cambridge Isotope Laboratories, degassed
by freeze-pump-thaw cycles, and dried over CaH2 or activated
Preparation of (dtbpe)Cu-C(N2)dmp (5). To a cold (-35 °C)
ether solution of 1 (70.9 mg, 0.2 mmol in 5 mL of Et2O) was
added a 2 mL cold ether solution of LiN(i-Pr)2 (21.4 mg,
0.2 mmol, -35 °C) at once. After the mixture was stirred for
30 min at room temperature, the bright red solution was added
to a cold suspension of [(dtbpe)CuCl]2 (3; 133.1 mg, 0.1 mmol,
5 mL of Et2O, -35 °C). The mixture turned bright yellow and
was stirred for additional 30 min at room temperature. The
volatiles were removed under reduced pressure, and the residual
yellow solids were extracted with pentanes. Analytically pure 5
was isolated by crystallization from a concentrated pentane
solution at -35 °C (110 mg, 0.15 mmol, 75%). 1H NMR
(20 °C, 500.13 MHz, C6D6): δ 7.572 (m, C6H3, 3H), 7.09 (s,
CH, 1H), 6.95 (s, C6H2, 4H), 2.43 (s, CH3, 6H), 2.36 (s, CH3,
12H), 1.21 (m, C2H4, 4H), 1.03 (m, -C(CH3)3). 31P{1H} NMR
(20 °C, 202.47 MHz, C6D6): δ 44.22 (s). 13C{1H} NMR (20 °C,
125.75 MHz, C6D6): δ 198.31 (s, -C(dN2)dmp), 152.15 (s), 148.62
(s), 140.13 (s), 135.18 (d, JCP = 6 Hz), 131.33 (s), 129.46 (s), 120.48
(s), 118.11 (s), 34.18 (t, -C2H4-, JCP = 5 Hz), 31.81 (t, -C(CH3)3,
JCP = 8 Hz), 20.32 (s, o-C6H2(CH3)3), 20.01 (s, p-C6H2(CH3)3),
19.01 (t, -C(CH3)3, JHP = 15 Hz). IR (CaF2, Fluorolube): 2042
(m, νCdN), 1412 (s, νNdN) cm-1. Anal. Calcd for C43H65N2CuP2:
C, 70.2; H, 8.91; N, 3.81. Found C, 70.2; H, 8.84; N, 3.57.
˚
˚
4 A molecular sieves. Celite, alumina, and 4 A molecular sieves
were activated by evacuation overnight at 180 °C. (dmp)I,4
{(dtbpe)Cu(μ-Cl)}2 (3),7 and (IPr)Cu(Cl) (4)8 were prepared
according to the literature methods. All other chemicals were
used as received. Elemental analyses were performed by Mid-
1
west Microlab (Indianapolis, IN). H NMR spectra were re-
corded on Bruker 500 MHz NMR spectrometers and reported
with reference to residual C6D5H in C6D6 (7.16 ppm) and CHCl3
in CDCl3 (7.24 ppm). X-ray diffraction data were collected on a
Siemens Platform goniometer with a charged coupled device
(CCD) detector. Structures were solved by direct methods using
the SHELXTL (version 5.1) program library (G. Sheldrick,
Bruker Analytical X-ray Systems, Madison, WI).
Preparation of (dmp)CHdO. A cold solution of 4 mL of 1.6 M
n-BuLi in hexanes was added to a solution of 2.2 g (5 mmol) of
(dmp)I in 25 mL of cyclohexane.4b After the mixture was stirred
at room temperature for 12 h, 0.4 mL (0.377 g, 5.2 mmol) of dry
dimethylformamide was added to the reaction mixture. The
reaction mixture was heated to reflux for 2 h and then quenched
with 50 mL of H2O at 0 °C. The organic layer was separated and
the aqueous layer extracted with 3 ꢀ 10 mL of diethyl ether. The
combined organic layers were dried over MgSO4 and filtered,
and the solvent was removed under reduced pressure to yield a
white crystalline solid. Further purification on a silica column
using hexanes as an eluent yielded 1.2 g (3.5 mmol, 70%) of pure
product. 1H NMR (22 °C, 500.13 MHz, CDCl3): δ 9.66 (s, CHO,
1H), 7.67 (t, C6H3, 1H, JHH = 7.6 Hz), 7.18 (d, C6H3, 2H,
JHH = 7.6 Hz), 6.96 (s, C6H2, 4H), 2.35 (s, CH3, 6H), 1.97 (s,
CH3, 12H). GC MS (m/z): 324 (Mþ), 310.
(IPr)Cu-CN2(dmp) (6). This complex was prepared and
isolated in a manner analogous to that described above for 5,
except that (IPr)Cu(Cl) (4; 98 mg, 0.2 mmol) was used instead of
3. 6 was isolated in 82% yield (132 mg) as a bright yellow solid.
1H NMR (20 °C, 500.13 MHz, C6D6): δ 7.23 (t, IPrAr, 2H,
J
J
HH = 8 Hz), 7.07 (d, IPrAr, 4H, JHH = 8 Hz), 6.98 (t, C6H3, 1H,
HH = 7 Hz), 6.89 (d, C6H3, 2H, JHH = 7 Hz), 6.79 (s, C6H2,
4H), 6.18 (s, CHdCH, 2H), 2.55 (sept, -CH(CH3)3, 4H,
JHH = 7 Hz), 2.33 (s, p-CH3, 6H), 2.08 (s, o-CH3, 12H), 1.15
(d, -CH(CH3)3, 12H, JHH = 7 Hz), 1.00 (d, -CH(CH3)3, 12H,
JHH = 7 Hz). 13C{1H} NMR (20 °C, 125.75 MHz, C6D6): δ
183.4, 145.3, 140.8, 140.2, 135.9, 135.2, 134.2, 130.5, 128.9,
128.3, 124.4, 123.2, 122.6, 28.9, 24.0, 23.9, 21.1. IR (CaF2,
Fluorolube): 1975 (s, νNdN), 1459 (m, νCdN) cm-1. Anal. Calcd
for C52H61N4Cu: C, 77.5; H, 7.63, N 6.95. Found C, 77.3; H,
7.54; N, 7.09.
Preparation of (dmp)CHdN2H2. A 100 mL round-bottom
flask was charged with 1.028 g (3 mmol) of (dmp)CHdO, 50 mL
of ethanol, and 5 mL (100 mmol) of N2H4 H2O. The mixture
3
was heated at reflux for 12 h. After the mixture was cooled in an
ice bath for 30 min, a crystalline precipitate was filtered and
dried under reduced pressure to give 1.00 g (2.8 mmol, 93%) of
the hydrazone (dmp)CHdN2H2. 1H NMR (20 °C, 500.13 MHz,
C6D6): δ 7.20 (s, CHN, 1H), 7.13 (t, C6H3, 1H, JHH = 7.5 Hz),
6.96 (d, C6H3, 2H, JHH = 7.5 Hz), 6.89 (s, C6H2, 4H), 4.21 (s,
NH2, 2H), 2.22 (s, CH3, 6H), 2.12 (s, CH3, 12H). 13C{1H} NMR
(20 °C, 125.77 MHz, C6D6): δ 140.79 (s, CAr), 139.24 (s, CAr),
138.32 (s, CAr), 136.19 (s, CAr), 135.75 (s, CAr), 132.65 (s, CHN),
129.34 (s, CAr), 128.36 (s, CAr), 127.98 (s, CAr), 21.24 (s, CH3),
20.95 (s, CH3). GC MS (m/z): 356 (Mþ), 341.
Preparation of (dtbpe)Cu-N(n-Bu)NdCH(dmp) (7). To a
cold (-35 °C) solution of 1 (70.9 mg, 0.2 mmol in 5 mL of Et2O)
was added 0.1 mL of n-BuLi (2 M in cyclohexane). After the
mixture was stirred for 30 min at room temperature, the solu-
tion turned bright red and was added to a cold suspension
of {(dtbpe)Cu(μ-Cl)}2 (3; 133 mg, 0.1 mmol, 5 mL of Et2O,
-35 °C). The mixture turned bright yellow and was stirred for an
additional 30 min at room temperature. The volatiles were
removed under reduced pressure and the residual yellow solids
extracted with pentanes. 4 was isolated by crystallization from
Preparation of N2CH(dmp) (1). To a mixture of (dmp)-
CHdN2H2 (1.00 g, 2.8 mmol), 0.94 g (4.24 mmol) of HgO,
and 0.5 g (3.52 mmol) of Na2SO4 in 10 mL of diethyl ether was
added a 0.5 mL saturated KOH solution in ethanol with
vigorous stirring. The orange suspension turned dark green,
1
a concentrated pentane solution at -35 °C (75%). H NMR
(20 °C, 500.13 MHz, C6D6): δ 7.07 (m, C6H3, 3H), 6.99 (s, CH,
1H), 6.91 (s, C6H2, 4H), 3.0 (t, R-CH2, 2H, JHH = 7 Hz), 2.37 (s,
CH3, 12H), 2.31 (s, CH3, 6H), 1.41 (m, β-CH2, γ-CH2 4H), 1.21
(t, C2H4, 4H, JHP = 3 Hz), 1.09 (t, δ CH3, 3H, JHH = 7 Hz), 0.89
(t, C(CH3)3, 18H, JHP = 3 Hz), 31P{1H} NMR (20 °C, 202.47
MHz, C6D6): 29.04 (s). 13C{1H} NMR (20 °C, 125.75 MHz,
(10) Gunnoe, B. T. Eur. J. Inorg. Chem. 2007, 1185–1203.

6138 Organometallics, Vol. 28, No. 20, 2009
Iluc et al.
C6D6): δ 142.75 (s), 138.51 (s), 136.26 (d, JCP = 3 Hz), 133.72 (s),
129.23 (s), 128.29 (s), 121.19 (s), 116.04 (s), 62.30 (s, dCH), 36.70
(s, R-CH2), 33.33 (t, C2H4, JCP = 3 Hz), 30.26 (t, C(CH3)3,
Acknowledgment. This work was supported by the
National Science Foundation through Grant No. CHE-
0615274 to G.L.H.
JCP = 5 Hz), 21.57 (s, o-C6H2(CH3)3), 21.39 (s, p-C6H2(CH3)3),
21.14 (s, β-CH2), 20.18 (t, C(CH3)3, JHP = 13 Hz), 14.99 (s,
γ-CH2), 14.23 (s, δ-CH3). 13C NMR (20 °C, 125.77 MHz, C6D6):
δ 62.32 (t, NdCH, JCH = 131 Hz). IR (CaF2, Nujol): 1479 (m,
ν
N, 3.53. Found: C, 71.0; H, 9.62; N, 3.79.
Supporting Information Available: Text, tables, figures, and
CIF files giving complete crystallographic details for 5-7
characterization data. This material is available free of charge
via the Internet at http://pubs.acs.org.
NdN) cm-1. Anal. Calcd for C47H75N2CuP2: C, 71.1; H, 9.53;