Structure of Bis(cyclopropyl)bis(dimethylphenylphosphine)platinum(II), [formula omitted]. Relationship between Structural and ¹J(¹⁹⁵Pt-³¹P) Data and Position of Cyclopropyl Group in Trans-Influence Series

The structure of cis-bis(cyclopropyl)bis(dimethylphenylphosphine)platinum(II), [formula omitted], has been determined crystallographically at −133 (2) °C and consists of discrete molecules of the neutral complex. The complex crystallizes from pentane in the triclinic space group C_i¹-P1̄ with two formula units in a unit cell of dimensions a = 11.055 (3) Å, b = 11.457 (3) Å, c = 9.897 (2) Å, α = 112.46 (1)°, β = 96.43 (1)°, γ.67.73 (1)°. The structure was solved from Patterson and electron density maps. Full-matrix least-squares refinement has led to a final value of the R index on F² of 0.068 based on 8749 reflections and 226 variables. The conventional R index on F for those 7210 reflections having F_o² > 3 σ(F_o²) is 0.039. This complex of Pt(II) possesses nearly square-planar geometry, P(1)-Pt-P(2) = 94.86 (4)°, C(1)-Pt-C(4) = 89.91 (18)°. The cyclopropyl rings are equilateral with average C-C distances of 1.506 (13) Å and C-C-C angles of 60.00 (80)°. Some important molecular parameters are Pt-C(1) = 2.086 (4) Å, Pt-C(4) = 2.070 (4) Å, Pt-P(1) = 2.302 (1) Å, and Pt-P (2) = 2.291 (1) Å. Examination of the structural and ³¹P{¹H} NMR data and comparison of these data with those of other Pt(II) complexes suggest placement of the cyclopropyl group in the trans-influence series between metallocycloalkanes and alkyl groups, such as methyl and neopentyl.