R.J. Bowen et al. / Inorganica Chimica Acta 362 (2009) 3172–3180
3173
night at room temperature compound 2 was obtained as a colour-
2. Experimental
less solid (0.260 g, 95%).
2.1. Preparations
2.1.3. Synthesis of [Cu{(Me3Si)NC(But)CH(SiMe3)PPh2}2]ClO4 (3)
A solution of 0.357 g (0.83 mmol) 1 in CH2Cl2 (20 mL) was
added dropwise to a suspension of Cu(NCCH3)4ClO4 (0.130 g,
0.040 mmol) in CH2Cl2 (5 mL). The resulting pale yellow solution
was stirred overnight, then concentrated and layered with Et2O
(approx. 15 mL) to give on standing colourless crystals of 3
All manipulations were carried out under argon, using standard
Schlenk techniques. Solvents were distilled from drying agents and
degassed. Anhydrous CuCl was purchased from Sigma–Adrich,
Cu(NCCH3)4ClO4 [6], Me2SAuCl [7] and Me3SiN@C(But)CH(Si-
Me3)PPh2 (1) [4] were synthesised according to literature proce-
dures. NMR spectra were recorded in CDCl3, CD2Cl2, CD3CN or
DMSO-d6 at ambient probe temperature using the following Bruker
instruments: DRX 400 (1H 400.13, 31P 161.9, 13C 100.6 MHz),
Avance 300 (1H 300.13, 13C 75.48), Avance I (1H 400.13, 31P
161.98 MHz), Avance III (1H, 400.03, 31P 161.94, 13C 100.59, 29Si
79.47 MHz) or AC200 (1H 200.13, 31P 81.01, 13C 50.32 MHz) and
referenced internally to residual solvent resonances (chemical shift
data in d). 13C and 31P NMR spectra were all proton-decoupled. Ele-
mental analyses were determined by the microanalytic laboratory
of the Westfälische Wilhelmsuniversität Münster. The following
abbreviations are used throughout the experimental section:
s = singlet, bs = broad singlet, d = doublet, dd = doublet of doublet,
m = multiplet; t = triplet, vt = virtual triplet. Coupling constants
(J) are given in Hz.
(0.35 g, 84%). Anal. Calc. for C50H81ClCuN2O4.5P2Si4 [3ꢁ(Et2O)0.5
;
1055.46]: C, 56.90; H, 7.74; N, 2.65. Found: C, 56.59; H, 7.67; N,
2.61%; 1H NMR (CD3CN) d: 0.01 (9H, s, br, CSiMe3), 0.27 (9H, s,
2
NSiMe3), 0.78 (9H, s, But), 4.16 (1H, d, JHP = 10.1 Hz, PCH), 7.36
(3H, m, m/p-Ph), 7.45 (3H, m, m/p-Ph), 7.58 (2H, m, o-Ph), 7.79
(2H, m, o-Ph). 31P NMR (CD3CN) d: 1.3 (s, PPh2). 13C NMR (CD3CN)
1
d: 1.2 (s, CSiMe3), 3.8 (NSiMe3), 29.6 (CMe3), 41.1 (d, JCP = 6.2 Hz,
3
CHP), 44.7 (s, CMe3), 129.5 (d, JCP = 8.5 Hz, m-C), 130.0 (d,
3JCP = 8.9 Hz, m-C), 131.0 (s, p-C), 131.3 (s, p-C), 135.4 (d,
2
2JCP = 6.4 Hz, o-C), 135.8 (d, JCP = 4.5 Hz, o-C), 137.2 (d, not re-
1
solved, ipso-C), 138.8 (d, JCP = 6 Hz, ipso-C), 186.1 (bs, CN). IR
(cmꢀ1): mCN 1672.
2.1.4. Synthesis of [Cu{HNC(But)CH(SiMe3)PPh2}2]ClO4 (4)
Dry Cu(NCCH3)4ClO4 was exposed for 3 days in an open con-
tainer to humid air until the colourless solid had turned pale
blue-green. 0.130 g (0.41 mmol) of this solid were then suspended
in CH2Cl2 and the reaction mixture was treated with a solution of 1
(0.400 g, 0.94 mmol). There was a colour change from blue to yel-
low. The reaction mixture was stirred at room temperature over-
night, then filtered by means of a cannula, and the filtrate was
concentrated and layered with Et2O to give colourless crystals.
Concentration of the mother liquid and layering gave a second
and a third fraction resulting in a total yield of 0.24 g (67%) of com-
pound 4. Anal. Calc. for C42H60ClCuN2O4P2Si2 (874.07): C, 57.71; H,
6.92; N, 3.20. Found: C, 57.24; H, 6.91; N, 3.08%. The NMR spectra
indicate the presence of two isomers in solution (the given d values
represent the minor/major isomer). 1H NMR (CD2Cl2; ratio 1:1.5) d:
0.19 (9H, bs, CSiMe3), 0.92/0.94 (5.5/3.5H, s, But), 3.66 (1H, m,
PCH), 7.40 (3H, m, m/p-Ph), 7.56 (3H, m, m/p-Ph), 7.79 (4H, m,
o-Ph), 9.20/9.54 (0.6/0.4H, bs, NH). 31P NMR (CD2Cl2) d: 13.4 (bs,
PPh2). 1H NMR (CDCl3; ratio 1:3) d: 0.175/0.185 (9H, s, CSiMe3),
0.95/0.96 (9H, s, But), 3.63/3.48 (1H, m, PCH), 7.34–7.80 (10H, m,
Ph), 9.31/10.30 (1H, bs, NH). 31P NMR (CDCl3) d: 13.3/14.8 (s, br,
PPh2). 1H NMR (CD3CN 300 K; ratio 1:1.9) d: 0.170/0.175 (9H, s,
CSiMe3), 0.90/0.95 (9H, s, But), 3.83/3.93 (1H, bs, PCH), 7.39 (3H,
bs, m/p-Ph), 7.53 (3H, bs, m/p-Ph), 7.83 (2H, bs, o-Ph), 7.92 (2H,
bs, o-Ph), 9.36/9.62 (1H, bs, NH). 31P NMR (CD3CN 300 K) d: 13.5/
18.1 (bs, PPh2). 29Si (CD3CN, 300 K) d: 4.62/4.66 (overlapping vt,
JSiP ꢂ 7 Hz; SiMe3). 13C NMR (CD3CN 300 K) d: 1.7/1.9 (vt,
JCP = 4.2/4.6 Hz, SiMe3), 27.5/27.9 (s, CMe3), 39.2/39.3 (vt,
JCP = 7.0/7.0 Hz, CHP), 42.3 (s, CMe3, only 1 signal observed),
130.0 (vt, JCP = 9.6 Hz, Ph), 130.4 (vt, JCP = 9.6 Hz, Ph), 132.0 (s,
Ph), 132.4(s, Ph), 134.4 (vt, JCP = 21.2, ipso-C), 135.0 (overlapping
m, Ph), 136.6 (vt, JCP = 20.0 Hz, ipso-C), 198.7 (vt, JCP = 3.6 Hz, CN).
IR (cmꢀ1): mNH 3294, mCN/C@C 1587/1572.
2.1.1. Synthesis of [Cu{(Me3Si)NC(But)CH(SiMe3)PPh2}Cl]2 (2)
Solid CuCl (0.182 g, 1.84 mmol) was added to a solution of 1
(0.785 g, 1.84 mmol) in CH2Cl2 (20 mL) at room temperature and
the mixture was stirred overnight. The slightly turbid reaction mix-
ture was then filtered by means of a cannula. The filtrate was con-
centrated and layered with hexane to give 2 as a colourless solid
(0.7 g, 72.2%). Anal. Calc. for C24H38ClCuNPSi2 (526.71): C, 54.73;
H, 7.27; N, 2.66. Found: C, 54.77; H, 7.26; N, 2.67; 1H NMR (CD2Cl2)
d: 0.09 (9H, d, 4JHP = 0.8 Hz, CSiMe3), 0.36 (9H, s, NSiMe3), 0.85 (9H, s,
But), 4.18 (1H, d, 2JHP = 15.4, PCH), 7.36 (3H, m, m/p-Ph), 7.48 (3H, m,
m/p-Ph), 7.72 (2H, m, o-Ph), 7.95 (2H, m, o-Ph). 31P NMR (CD2Cl2) d:
3
14.9 (s, PPh2). 13C NMR (CD2Cl2) d: 1.1 (d, JCP = 4.8 Hz, CSiMe3),
1
3.6 (NSiMe3), 29.5 (CMe3), 40.0 (d, JCP = 20.1 Hz, CHP), 43.6 (s,
3
3
CMe3), 129.2 (d, JCP = 10.5 Hz, m-C), 129.7 (d, JCP = 10.5 Hz, m-
C), 131.5 (d, 4JCP = 2.1 Hz, p-C), 131.9 (d, JCP = 1.9 Hz, p-C), 132.0
(d, JCP = 39.8 Hz, ipso-C), 133.9 (d, JCP = 34.4 Hz, ipso-C), 134.6
(d, JCP = 15.7 Hz, o-C), 135.0 (d, JCP = 16.7 Hz, o-C), 183.8 (d,
2JCP = 3.7 Hz, CN); MS (EI) m/z: 525–530(expected isotopic pat-
tern) (0.3%, [M(monomer)]+), 486 (1.2%, [MꢀBut]+). IR (cmꢀ1):
4
1
1
2
2
m
CN 1686.
1H NMR (CDCl3) d: 0.09 (9H, d, 4JHP = 0.5 Hz, CSiMe3), 0.38 (9H, s,
NSiMe3), 0.83 (9H, s, But), 4.13 (1H, d, 2JHP = 15.4, PCH), 7.37 (3H, m,
m/p-Ph), 7.47 (3H, m, m/p-Ph), 7.70 (4H, m, o-Ph), 7.93 (4H, m, o-
Ph). 31P NMR (CDCl3) d: 12.8 (s, PPh2). 29Si (CDCl3) d: ꢀ9.3 (bs,
2
NSiMe3), 3.3 (d, JSiP = 4.7 Hz, CHSiMe3). 13C NMR (CDCl3) d: 0.6
3
(d, JCP = 4.7 Hz, CSiMe3), 3.2 (NSiMe3), 28.9 (CMe3), 39.4 (d,
1JCP = 17.7 Hz, CHP), 42.9 (s, CMe3), 128.2 (d, JCP = 10.4 Hz, m-C),
3
3
4
128.7 (d, JCP = 10.4 Hz, m-C), 130.4 (d, JCP = 1.8 Hz, p-C), 130.9
4
1
(d, JCP = 1.4 Hz, p-C), 131.7 (d, JCP = 36.2 Hz, ipso-C), 133.4 (d,
1JCP = 32.2 Hz, ipso-C), 133.9 (d, JCP = 15.7 Hz, o-C), 134.2 (d,
2
2JCP = 16.8 Hz, o-C), 182.7 (d, JCP = 3.7 Hz, CN).
2
2.1.5. Synthesis of [Cu{HNC(But)CH2PPh2}2]ClO4 (5) from 3
A solution of 0.5 mL CH3OH (0.040 g, 1.25 mmol) was added
dropwise to a solution of 0.650 g (0.65 mmol) of 3 in CH2Cl2
(20 mL) at 0 °C. The solution was allowed to warm to room tem-
perature and stirred overnight. The solvent was removed in vacuo,
the remaining solid was redissolved in CH2Cl2 and layered with
Et2O to give colourless crystals of 5 (0.45 g, 95%). Anal. Calc. for
C36H44ClCuN2O4P2 (729.70): C, 59.24; H, 6.08; N, 3.84. Found: C,
59.22; H, 6.12; N, 3.71%. 1H NMR (CD2Cl2) d: 1.22 (9H, s, But),
3.47 (2H, bs, PCH), 7.38 (10H, bs, Ph); 9.62 (1H, bs, NH). 31P NMR
2.1.2. Reaction of CuCl2 with 1
Solid CuCl2 (0.070 g, 0.052 mmol) was added to a solution of 1
(0.437 g, 1.02 mmol) in CH2Cl2 (20 mL). The initial dark green solu-
tion turned yellow after 1 h. The solution was stirred overnight and
concentrated to approximately 3 mL and layered with hexane (ap-
prox. 10 mL) to give a few colourless crystals at ꢀ45 °C. The reac-
tion mixture was then concentrated in vacuo until a colourless
solid started to crystallise at the glass wall. After standing over-