Inorganic Chemistry, Vol.34, No.9, 2300-2305, 1995
Heavy-Metal Complexes of Oxa-Crowned Derivatives of Dithiomaleonitrile
An improved synthesis of 1,4,7-trioxa-10,13-dithiacyclopentadec-11-en-11,12-dicarbonitrile, 2, and 1,4,7,10-tetraoxa-13,16-dithiacyclooctadec-14-en-14,15-dicarbonitrile, 3, and their coordination chemistry with Ag(I) are presented. The metal complexes have been investigated by X-ray structural and spectroscopic methods. The complex [2 . Ag]BF4, 6, forms colorless crystals in the triclinic space group P (1) over bar with unit cell parameters a = 8.020(4) Angstrom, b = 16.032(5) Angstrom, c = 16.116(7) Angstrom, alpha = 116.62(2)degrees, beta = 102.34(2)degrees, gamma = 91.71(2)degrees, and Z = 4. The structure of 6 contains two unique, cocrystallized, I:1 Ag complexes, a polymeric form and a discrete monomeric form. In both cases, the five macrocyclic donor atoms ligate the Ag(I) ion in an endocyclic fashion. The monomeric complex is further coordinated to a F atom from the BF4 anion, while in the polymeric form the Ag(I)-macrocycle units are linked by the coordination of a nitrile N atom from a neighboring macrocycle. The complex [3 . Ag]BF4, 7, crystallizes in the orthorhombic space group P2(1)2(1)2(1) with unit cell parameters a 10.074(4) Angstrom, b = 12.575(4) Angstrom, c = 16.144(6) Angstrom, and Z = 4. The structure of 7 is polymeric and consists of an endocyclic Ag(I) ion coordinated by three of the four macrocyclic O donor atoms and only one S atom. As in the polymer form of 6, the links between Ag-macrocycle units are through the coordination of a nitrile N atom from a neighboring macrocycle. NMR (C-13) studies confirm that the complex persists in methanol solution, with an average structure that involves the coordination of all macrocyclic heteroatoms in both 6 and 7.
Keywords:X-RAY STRUCTURES;THIOETHER CHEMISTRY;CRYSTAL-STRUCTURES;SILVER(I) COMPLEXES;MOLECULAR-STRUCTURE;REDOX PROPERTIES;4;7;13;16-TETRAOXA-1;10-DITHIACYCLOOCTADECANE;MERCURY;ETHERS;LIGAND