Concomitant polymorphic behavior of di-μ-thiocyanato-κ2 N:S;κ2 S:N-bis[bis(tri-p-fluorophenylphosphine-κP)silver(I)

Abstract

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, ½, 0) from the origin in the asymmetric unit. Polymorph (II) has one and a half molecules of [Ag2(SCN)2{P(4-FC6H4)3}4] in the asymmetric unit; the half molecule is situated at (0, 1, ½), while the full molecule is located at (1/3, ½, 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.