Omondi Bernard, Meijboom Reinout
Department of Chemistry, University of Johannesburg, PO Box 524, Auckland Park 2006, Johannesburg, South Africa.
Acta Crystallogr B. 2010 Feb;66(Pt 1):69-75. doi: 10.1107/S0108768109048769. Epub 2010 Jan 22.
The structures of two polymorphs, both monoclinic P2(1)/n [polymorph (I)] and P2(1)/c [polymorph (II)], of di-mu-thiocyanato-kappa(2)N:S;kappa(2)S:N-bis[bis(tri-p-fluorophenylphosphine-kappaP)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 [Ag(2)(SCN)(2){P(4-FC(6)H(4))(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-FC(6)H(4))(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) A in both polymorphs. The Ag-S distances are 2.5773 (7) A in (I) and 2.5457 (5), 2.5576 (5) and 2.5576 (5) A in (II). The full molecule in polymorph (II) has slightly shorter Ag-N bond distances [2.375 (1) and 2.367 (2) A] compared with the half molecules in both polymorphs [2.409 (2) A in (II) and 2.395 (2) A in (I)]. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plot analysis.
已在100 K下测定了二 - μ - 硫氰酸根 - κ(2)N:S;κ(2)S:N - 双[双(对 - 三氟苯基膦 - κP)银(I)]配合物的两种多晶型结构,均为单斜晶系P2(1)/n [多晶型(I)]和P2(1)/c [多晶型(II)]。在这两种多晶型中,配合物均具有双核结构,其中银(I)与两个膦配体和两个桥连硫氰酸根阴离子配位,形成具有扭曲四面体几何构型的配合物。多晶型(I)在不对称单元中,相对于原点,在(0, 1/2, 0)处只有[Ag(2)(SCN)(2){P(4 - FC(6)H(4))(3)}(4)]分子的一半。多晶型(II)在不对称单元中有一个半[Ag(2)(SCN)(2){P(4 - FC(6)H(4))(3)}(4)]分子;半个分子位于(0, 1, 1/2),而完整分子相对于原点位于(1/3, 1/2, 1/3)。在两种多晶型中,Ag - P键长范围为2.4437(4)至2.4956(7) Å。Ag - S距离在(I)中为2.5773(7) Å,在(II)中为2.5457(5)、2.5576(5)和2.5576(5) Å。与两种多晶型中的半个分子相比[在(II)中为2.409(2) Å,在(I)中为2.395(2) Å],多晶型(II)中的完整分子具有稍短的Ag - N键长[2.375(1)和2.367(2) Å]。使用均方根重叠计算以及半正态概率图分析对这两种多晶型进行了比较。