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

By reaction of Pb(CH 3 COO) 2 · 3H 2 O with Na 2 S 2 C=C(CN) 2 · 3H 2 O in water, α-PbS 2 C=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 P2 1 /n and a = 11.879(5), b = 12.027(5), c = 4.655(1) Å, β = 96.94(3)°, Z = 4. The compound contains PbS 2 C 4 N 2 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 PbS 2 C = C(CN) 2 groups with a stereochemically active lone-pair, and dimers Pb 2 (S 2 C 4 N 2 ) 2 with Pb···Pb distance = 3.80 Å.