TY - JOUR
T1 - Stereochemical Consequences of Chelated, Bridging Phosphino-Phosphido Ligands. Single-Crystal X-ray Diffraction and Multinuclear [1H, 31P{1H}, 195Pt{1H}] NMR Studies on the Stereochemistry of Dichlorobis[(3-(di(cyclohexyl or phenyl)phosphino)propyl)phenylphosphido]diplatinum(II) Diastereomeric Complexes and Their Dipalladium(II) Analogues
AU - Glaser, Robert
AU - Kountz, Dennis J.
AU - Waid, Robert D.
AU - Gallucci, Judith C.
AU - Meek, Devon W.
PY - 1984/1/1
Y1 - 1984/1/1
N2 - Tertiary-secondary diphosphine ligands of the type R2PCH2CH2CH2P(Ph)H provide rational and controlled routes to phosphido-bridged bimetallic complexes. The 1H, 31P{1H}, and 195Pt{1H} NMR data on a series of phosphido-bridged diplatinum(II) and dipalladium(II) complexes and the crystal and molecular structures of two phosphido-bridged diplatinum(II) complexes are reported. The compound dl-[PtCl{PhP(CH2)3P(C6H11)2}]2 was synthesized from PtCl2{Ph(H)- PCH2CH2CH2P(C6H11)2} in THF and crystallized from dichloromethane/ethanol as chiral crystals belonging to the orthorhombic space group [formula omitted] in a cell of dimensions a = 15.269 (1) Å, b = 17.119 (2) Å, c = 16.605 (1) Å, with Z = 4 and V = 4341 (1) Å3 at 148 K. The structure was refined to an R index on F of 0.027 for 4667 observed reflections (Fo2 ≥ 3 [σ(Fo2)]) and 368 variables. By use of the Bijvoet method, the data crystal was found to have the (Sn,Sn) absolute configuration. In the chiral diplatinum molecule, two nonbonded platinum atoms (Pt⃯Pt = 3.5454 (5) Å) are bridged by two phosphido groups, the tetraatomic [formula omitted] core is bent [dihedral angle = 19.1(2)°], and the two phenyl groups are cis. The meso [PtCl{PhP(CH2)3P(C6H11)2}]2 crystallizes from dichloromethane/ethanol with Z = 2 in the monoclinic space group [formula omitted] in a cell of dimensions a = 11.1177 (7) Å,b= 12.466 (1) Å, c = 16.371 (1) Å, β = 99.751 (1)°, with V= 2236.1 (3) Å3 at 148 K. The structure was refined to an R index on F of 0.026 for 4365 observed reflections (Fo2 ≥ 3[σ(Fo2)]) and 227 variables. In the weio-diplatinum complex, two nonbonded platinum atoms [Pt⋯Pt = 3.5771 (2) Å] are bridged by two phosphido groups, the tetraatomic core is planar, and the two phenyl groups are trans. In a comparison of phosphido-bridged Pt(II) and Pd(II) dimers differing in core geometry, the δP value of the phosphido P atom is shifted −22 to −41 ppm in the planar diastereomer vis-à-vis the bent-core isomers. The magnitudes of some 31P{1H} and 195Pt{1H} NMR coupling constants (e.g., [formula omitted]) appear to be sensitive to the planar-/bent-core stereochemistry. The platinum chemical shift of meso-[PtCl{PhP(CH2)3P(C6H11)2}]2 is shielded +49 ppm relative to the value of the bent-core dl isomer. Comparisons of the 31P{1H} data between analogous Pt(II) and Pd(II) complexes, as well as with the planar Pt2(µ-PPh2)2 core in other complexes, are presented.
AB - Tertiary-secondary diphosphine ligands of the type R2PCH2CH2CH2P(Ph)H provide rational and controlled routes to phosphido-bridged bimetallic complexes. The 1H, 31P{1H}, and 195Pt{1H} NMR data on a series of phosphido-bridged diplatinum(II) and dipalladium(II) complexes and the crystal and molecular structures of two phosphido-bridged diplatinum(II) complexes are reported. The compound dl-[PtCl{PhP(CH2)3P(C6H11)2}]2 was synthesized from PtCl2{Ph(H)- PCH2CH2CH2P(C6H11)2} in THF and crystallized from dichloromethane/ethanol as chiral crystals belonging to the orthorhombic space group [formula omitted] in a cell of dimensions a = 15.269 (1) Å, b = 17.119 (2) Å, c = 16.605 (1) Å, with Z = 4 and V = 4341 (1) Å3 at 148 K. The structure was refined to an R index on F of 0.027 for 4667 observed reflections (Fo2 ≥ 3 [σ(Fo2)]) and 368 variables. By use of the Bijvoet method, the data crystal was found to have the (Sn,Sn) absolute configuration. In the chiral diplatinum molecule, two nonbonded platinum atoms (Pt⃯Pt = 3.5454 (5) Å) are bridged by two phosphido groups, the tetraatomic [formula omitted] core is bent [dihedral angle = 19.1(2)°], and the two phenyl groups are cis. The meso [PtCl{PhP(CH2)3P(C6H11)2}]2 crystallizes from dichloromethane/ethanol with Z = 2 in the monoclinic space group [formula omitted] in a cell of dimensions a = 11.1177 (7) Å,b= 12.466 (1) Å, c = 16.371 (1) Å, β = 99.751 (1)°, with V= 2236.1 (3) Å3 at 148 K. The structure was refined to an R index on F of 0.026 for 4365 observed reflections (Fo2 ≥ 3[σ(Fo2)]) and 227 variables. In the weio-diplatinum complex, two nonbonded platinum atoms [Pt⋯Pt = 3.5771 (2) Å] are bridged by two phosphido groups, the tetraatomic core is planar, and the two phenyl groups are trans. In a comparison of phosphido-bridged Pt(II) and Pd(II) dimers differing in core geometry, the δP value of the phosphido P atom is shifted −22 to −41 ppm in the planar diastereomer vis-à-vis the bent-core isomers. The magnitudes of some 31P{1H} and 195Pt{1H} NMR coupling constants (e.g., [formula omitted]) appear to be sensitive to the planar-/bent-core stereochemistry. The platinum chemical shift of meso-[PtCl{PhP(CH2)3P(C6H11)2}]2 is shielded +49 ppm relative to the value of the bent-core dl isomer. Comparisons of the 31P{1H} data between analogous Pt(II) and Pd(II) complexes, as well as with the planar Pt2(µ-PPh2)2 core in other complexes, are presented.
UR - http://www.scopus.com/inward/record.url?scp=0001048353&partnerID=8YFLogxK
U2 - 10.1021/ja00333a036
DO - 10.1021/ja00333a036
M3 - Article
AN - SCOPUS:0001048353
SN - 0002-7863
VL - 106
SP - 6324
EP - 6333
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 21
ER -