Structure of Bis(triphenylphosphine)(N-ethoxycarbonyldithiocarbimato)palladium(II), Formed by the Reaction of Excess Ethoxycarbonyl Isothiocyanate with Palladium(0) in the Presence of Triphenylphosphine

When a large excess of EtOCONCS is added to Pd(0) complexes in the presence of PPh₃ (Et = C₂H₅, Ph = C₆H₅), a compound of composition Pd(S₂ CNCOOEt)(PPh₃)₂ is isolated. On the basis of an x-ray diffraction study the compound is shown to be bis(triphenylphosphine)(N-ethoxycarbonyldithiocarbimato)palladium(II). The compound crystallizes in space group C_i¹-P1 of the triclinic system with two molecules in a unit cell of dimensions a = 13.371 (2) Å, b = 13.741 (3) Å, c = 10.995 (2) Å, α = 93.85 (1)°, β = 113.74 (1)°, γ = 95.30 (1)°, and V = 1829 ų. The structure has been solved by the heavy-atom method and refined by full-matrix least-squares techniques to a final value of the conventional R index on F_o of 0.042 based on 5794 unique reflections having F_o² ≥ 3σ(F_o²) collected by counter methods. The Pd atom is coordinated to two P atoms from the PPh₃ groups and to two S atoms of the S₂C=NCOOEt dithiocarbimato ligand in approximately a square-planar fashion. The Pd-P distances are 2.306 (1) and 2.333 (1) Å, and the Pd-S distances are 2.316 (1) and 2.343 (1) Å. The S-Pd-S angle is 75.03 (4)°, while the P-Pd-P angle is 98.89 (4)°. All five atoms in the inner coordination sphere are within 0.1 Å of the best least-squares plane defined by these atoms. The S-C bond lengths are 1.742 (4) and 1.754 (4) Å and the C-N bond length is 1.282 (5) Å. The comparable parameters within the inner coordination sphere agree very well with those found in the bis(N-cyanodithiocarbimato)nickelate(II) anion. In addition, these parameters differ but little from those of typical dithiocarbamate complexes.