A potentially seven-co-ordinate complex that is only five-co-ordinate;crystal and molecular structure of di-iodo(6,7,8,9-tetrahydro-16,22-di-methyl-5,10-dithia-15,23,24-triaza-17,21-methenodibenzo[a,i]cyclonona-decene-NN′N″)zinc(II)

Abstract

A crystal structure determination of the title complex has been carried out. Cell dimensions are a= 19.523(11), b= 8.491 (7). c= 18.792(11)Å, α= 79.6(1), β= 115.6(1), and γ= 96.4(1)°. The crystals are triclinic, space group P, wiith Z= 4. The two molecules in the asymmetric unit have similar geometries. The zinc atoms have five-co-ordinate square-pyramidal environments, being bonded to an axial [2.628(4), 2.620(3)Å] and an equatorial [2.540(4),2.558(4)Å] iodine atom and to three equatorial nitrogen atoms [Zn-N(pyridine) 2.103(17),2.101 (19)Å;Zn-N 2.235(15)—2.280(15)Å]. The sulphur atoms of the macrocycle are not bonded to the metal primarily because the four carbon atoms between them cannot an pproximately planar girdle.