2,6-dimethylphenyl isocyanide (0.106 g, 0.811 mmol) in that
Experimental
order. The mixture was stirred at room temperature for 3 h, and
the solvent was removed. The resulting residue was solidified
with diethyl ether and hexane to give a white powder, which was
recrystallized from CH2Cl2/hexane to produce white crystals of
trans-Pt[CN4(R)]2(PMe3)2 (R = 2,6-Me2C6H3), 10 (0.213 g).
Thermal treatment of 10 in THF/CH2Cl2 (3 : 2 v/v ratio) at
General, materials and measurements
All manipulations of air-sensitive compounds were performed
under N2 or argon with the use of standard Schlenk techniques.
Solvents were distilled from Na–benzophenone. The analytical
laboratories at Basic Science Institute of Korea and at Kang-
nung National University carried out the elemental analyses.
IR spectra were recorded on a Perkin-Elmer BX spectro-
photometer. NMR (1H, 13C{1H} and 31P{1H}) spectra were
obtained on JEOL Lamda 300 MHz spectrometer. Chemical
shifts were referenced to internal Me4Si and to external 85%
H3PO4. Pd(N3)2L2 (L = PMe3, PEt3, PMe2Ph; L2 = depe, dppp)
and Pt(N3)2L2 (L = PMe3 or PEt3) were prepared by ligand-
exchange reactions of Pd(N3)2(tmeda)22 (tmeda = N,N,N Ј,NЈ-
tetramethylethylenediamine) and Pt(N3)2(COD)22 (COD =
cycloocta-1,5-diene) with corresponding tertiary or chelating
phosphine ligands. Ni(N3)2L2 (L = PMe3, PEt3; L2 = dppe)
were prepared by the literature method.23 2,6-Diethylphenyl
isocyanide was prepared as described in the literature.24
60 ЊC for 5 h gave the carbodiimido complex, Pt[CN (R)](N᎐C᎐
᎐ ᎐
4
N–R)(PMe3)2 (11) in 60% yield. Direct reactions of Pt(N3)2L2
(L = PMe3 or PEt3) with 2,6-dimethylphenyl isocyanide at
60 ЊC for 5 h also produce the same complexes, Pt[CN4(R)]-
(N᎐C᎐ N–R)(PMe ) {(L = PMe (11), PEt (12)) in, 54 and 92%
᎐ ᎐
3
2
3
3
yield, respectively.
Complexes 13–15. To a Schlenk flask containing Pd(N3)2-
(depe)2 (0.498 g, 1.26 mmol) was added THF/CH2Cl2 (10 cm3,
3 : 2 v/v ratio) and 2,6-dimethylphenyl isocyanide (0.329 g, 2.51
mmol). The mixture was heated at 60 ЊC for 5 h, and the initial
yellow solution gradually turned orange. After stirring, the
solvent was then removed completely, and the resulting residue
was solidified with diethyl ether and hexane to give a yellow
powder. Recrystallization from CH2Cl2/hexane gave yellow
Preparations
crystals of Pd[N᎐C᎐N-(R)] (depe) (R = 2,6-Me C H ), 13
᎐ ᎐
2
2
6
3
Complexes 3–6. To a Schlenk flask containing Pd(N3)2-
(PMe2Ph)2 (0.321 g, 0.688 mmol) was added THF/CH2Cl2
(10 cm3, 3 : 2 v/v ratio) and 2,6-dimethylphenyl isocyanide
(0.181 g, 1.38 mmol) in that order. The mixture was heated at
60 ЊC for 5 h, and the initial yellow solution slowly turned a
reddish orange. After stirring, the solvent was removed com-
pletely, and the resulting residue was solidified with CH2Cl2 and
diethylethertogiveyellowsolids. RecrystallizationfromCH2Cl2/
(0.397 g).
Complexes 14 and 15 were analogously prepared.
Reactions of 1 with acyl chloride derivatives. At room tem-
perature, benzoyl chloride (0.292 g, 2.07 mmol) was added to a
CH2Cl2 solution (5 cm3) containing complex 1 (0.542 g, 0.987
mmol). The initial orange solution instantly turned to a pale
yellow suspension. After stirring for 1 h, the reaction mixture
was fully evaporated in vacuo to give a pale yellowish residue.
The residue was extracted with diethyl ether (30 cm3), and the
solvent was removed in vacuo to give white solids. The products
were crystallized from diethyl ether, washed with hexane
(2 cm3 × 2) at 0 ЊC, and dried in vacuo to give white crystals of
PhCON(CN)-2,6-Me2C6H3 (0.432 g, 92%). Data for PhCON-
(CN)-2,6-Me2C6H3: νmax/cmϪ1: 2228 (s) and 1714 (s) (Found: C,
77.05; H, 5.72, N, 11.51. C16H14N2O requires C, 76.78; H, 5.64;
N, 11.19%); δH (300 MHz, CDCl3 at 25 ЊC) 2.38 (6H, s, CH3),
7.16–7.30 (3H, m, C6H3), 7.53–7.61 (3H, br, C6H5), and 7.97
(2H, br, C6H5); δC (75 MHz in CDCl3 at 25 ЊC) 17.7 (CH3),
109.7, 128.7, 129.0 (1C, s, CN), 129.3, 130.2, 130.5, 133.4,
135.9, 167.4 (1C, s, CO). The residual solids were identified as
PdCl2(PMe3)2 in 96% yield by comparison of the NMR data
with those of an authentic sample.
hexane gave yellow crystals of Pd(N᎐C᎐N–R) (PMe Ph)
᎐ ᎐
2
2
2
(R = 2,6-Me2C6H3), 3 (0.360 g).
Complexes 4–6 were prepared in a similar way to compound
3.
Complexes 7 and 8. To a Schlenk flask containing Pt(N3)2-
(PMe3)2 (0.430 g, 0.996 mmol) was added toluene (10 cm3) and
2,6-dimethylphenyl isocyanide (0.262 g, 1.99 mmol) in that
order. The mixture was heated at 80 ЊC for 24 h, during which
time the reaction mixture slowly turned to a colorless solution.
After stirring, the solvent was removed completely, and the
resulting residue was solidified with diethyl ether and hexane to
give a white powder. Recrystallization from CH2Cl2/hexane
gave white crystals of trans-Pt(N᎐C᎐N–R) (PMe ) (R = 2,6-
᎐ ᎐
2
3 2
Me2C6H3), 7 (0.338 g).
Complex 8 was analogously prepared.
The analogous reactions with phenyl chloroformate and
2-thiophenecarbonyl chloride also gave organic cyanamides,
PhO(CO)N(CN)-2,6-Me2C6H3 (85%) and C4H3SCON(CN)-
2,6-Me2C6H3 (91%), respectively. Data for PhO(CO)N(CN)-
2,6-Me2C6H3: νmax/cmϪ1: 2242 (s) and 1758 (s) (Found: C, 72.47;
H, 5.35, N, 10.77. C16H14N2O2 requires C, 72.16; H, 5.30; N,
10.52%); δH (300 MHz, CDCl3 at 25 ЊC) 2.43 (6H, s, CH3), 7.17–
7.32 (6H, m, C6H5), 7.39–7.44 (2H, br, C6H5); δC (75 MHz in
CDCl3 at 25 ЊC) 17.7 (CH3), 107.5, 120.8, 126.8, 129.2, 129.7,
130.1 (1C, s, CN), 130.4, 132.3, 136.1, 150.2 (1C, s, CO). Data
for C4H3SCON(CN)-2,6-Me2C6H3: νmax/cmϪ1: 2235 (s) and
1665 (s) (Found: C, 65.91; H, 4.79, N, 10.40. C14H12N2OS
requires C, 65.60; H, 4.72; N, 10.93%); δH (300 MHz, CDCl3 at
Ϫ60 ЊC) 2.37 (6H, s, CH3), 7.03 (1H, dd, J = 4, C6H5), 7.23–7.33
(3H, m, C6H5), 7.58 (2H, dd, J = 2, C4H3S); δC (75 MHz in
CDCl3 at Ϫ60 ЊC) 18.1 (CH3), 108.1, 127.9, 129.7, 130.1, 131.6,
132.4, 132.9, 133.9, 136.0, 137.4, 161.3 (1C, s, CO). NMR data
of C4H3SCON(CN)-2,6-Me2C6H3 at low temperature displayed
the presence of a minor conformer, and raising the temperature
of the sample resulted in a broad signal.
Similar reactions of Pt(N3)2(PMe3)2 with tert-butyl (or cyclo-
hexyl) isocyanide under the conditions described above gave
white solids. The isolated solids were identified as trans-
Pt[CN4(R)]2(PMe3)2 (R = tert-butyl, cyclohexyl) by comparing
their spectral data with those of a sample of the genuine
compound.10
Complexes 9. To a Schlenk flask containing Ni(N3)2(PMe3)2
(0.309 g, 1.048 mmol) was added CH2Cl2 (9 cm3) and 2,6-
dimethylphenyl isocyanide (0.275 g, 2.096 mmol) in that order.
The initial dark red solution immediately turned dark yellow
with the evolution of nitrogen. After stirring for 24 h at room
temperature, the solvent was completely evaporated under
vacuum, and then the resulting residue was solidified with
diethyl ether. The solids were filtered off and washed with
diethyl ether (2 × 2 cm3). Recrystallization from CH2Cl2/diethyl
ether gave brown crystals of trans-Ni[CN (R)](N᎐C᎐N–R)-
᎐ ᎐
4
(PMe3)2 (R = 2,6-Me2C6H3), 9 (0.240 g). Thermal treatment of 9
in THF/CH2Cl2 (3 : 2 v/v ratio) at 60 ЊC for 5 h converted to the
bis(carbodiimido) complex, Ni(N᎐C᎐N–R) (PMe ) (R = 2,6-
᎐ ᎐
2
3 2
Me2C6H3), 5 in 96% yield.
X-Ray structure determination
Complexes 10–12. To a Schlenk flask containing Pt(N3)2-
All X-ray data were collected with use of a Siemens P4 diffracto-
meter equipped with a Mo X-ray tube and a graphite crystal
(PMe3)2 (0.430 g, 0.996 mmol) was added CH2Cl2 (4 cm3) and
J. Chem. Soc., Dalton Trans., 2002, 3611–3618
3617
Kim, Yong-Joo
