Über Verbindungen subvalenter Hauptgruppenmetallkationen mit Dithiolaten, 1. Mitteilung. Das dimorphe Blei(II)-l,l-dicyanoethylen-2,2-dithiolat: Darstellung und Kristallstrukturen / Compounds of Subvalent Main Group Metal Cations with Dithiolates, 1. Contribution. Dimorphie Lead(II) l,l-Dicyanoethylene-2,2-dithiolate: Preparation and Crystal Structures

Abstract

Abstract By reaction of Pb(CH3COO)2 · 3H2O with Na2S2C=C(CN)2 · 3H2O in water, α-PbS2C=C(CN)2 is obtained. Hydrothermal conditions give small crystals of the α-and β-phase. The crystal structures of the two phases have been determined. The α-phase is monoclinic with space group P21/n and a = 11.879(5), b = 12.027(5), c = 4.655(1) Å, β = 96.94(3)°, Z = 4. The compound contains PbS2C4N2 molecules with Pb-S = 2.66 and 2.90 Å. Two molecules are connected to dimers with Pb···Pb = 4.44 Å. The β-phase also crystallizes monoclinically, space group C2/c, a = 9.613(1), b = 13.579(1), c -16.052(2) Å, β = 98.36°, and Z = 12. There are two independent lead positions, with the metals integrated in PbS2C = C(CN)2 groups with a stereochemically active lone-pair, and dimers Pb2(S2C4N2)2 with Pb···Pb distance = 3.80 Å.