Concomitant polymorphic behavior of di-μ-thiocyanato-κ² N:S;κ² S:N-bis[bis(tri-p-fluorophenyl-phosphine-P)silver(I)]

The structures of two polymorphs, both monoclinic P2₁/n [polymorph (I)] and P2₁/c [polymorph (II)], of di-μ- thiocyanato-κ² N:S;κ² S:N-bis[bis(tri-p- fluorophenylphosphine-κP)silver(I)] complexes have been determined at 100 K. In both polymorphs the complex has a dinuclear structure where the silver(I) coordinates to two phosphine ligands and two bridging thiocyanate anions to form complexes with distorted tetrahedral geometry. Polymorph (I) has just one half of the [Ag₂(SCN)₂{P(4-FC₆H₄) ₃}₄] molecule at (0, 1/2, 0) from the origin in the asymmetric unit. Polymorph (II) has one and a half molecules of [Ag ₂(SCN)₂{P(4-FC₆H₄)₃} ₄] in the asymmetric unit; the half molecule is situated at (0, 1, 1/2), while the full molecule is located at (1/3, 1/2, 1/3) from the origin. The Ag - P bond distances range from 2.4437 (4) to 2.4956 (7) Å in both polymorphs. The Ag - S distances are 2.5773 (7) Å in (I) and 2.5457 (5), 2.5576 (5) and 2.5576 (5) Å in (II). The full molecule in polymorph (II) has slightly shorter Ag - N bond distances [2.375 (1) and 2.367 (2) Å] compared with the half molecules in both polymorphs [2.409 (2) Å in (II) and 2.395 (2) Å in (I)]. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plot analysis.