Structural studies in the iron(III)/chloride/α,α'-diimine system. III : Crystal structures of tris(2,2'-bipyridine)iron(II) µ-Oxo-bis[trichloroferrate(III)] and of 'compound A', µ-Oxo-bis[cis-chlorobis-(1,10-phenanthroline)iron(III)] chloride solvate

Abstract

The crystal structure of [Fe(bpy)3] [CI3FeOFeCI3] (1) has been determined by single-crystal X-ray diffraction at 295 K, and refined by least squares to a residual of 0.058 for 2002 'observed' reflections. Crystals are monoclinic, P21/c, a 9.616(3), b 26.264(6), c 13.821(7) ?, ߠ99.68(2)ଠZ4. In the cation, Fe-N distances range from 1.956(9) to 1 .989(10) ?; in the anion, Fe-Cl distances range from 2.196(5) to 2.225(5) ?. Fe-O distances are 1.763(11) and 1.740(11) ?, and the Fe-O-Fe angle is 148.9(7)஠Recrystallization of 'compound A' from methanolic aqueous solution yields crystals with stoichiometry [{cis-Fe(phen)2Cl}2O]Cl2.nH2O( n 蠴.5) as established by structure determination (hampered by serious disorder); R is 0.09 for 749 'observed' reflections. Crystals are orthorhombic, Pcn2, a 18.05(1), b 13.83(1), c 10.481(6) ?, Z 2. The Fe-N distances trans to each other are 2.12(3) and 2.13(3) ?; Fe-N distances trans to Cl and O are 2.20(2) and 2.28(2) ?, respectively. Fe-CI is 2.34(1) and Fe-O 1.787(6) A; Fe-O-Fe is 161(1)஠For crystals from aqueous solution, an isomorphous but larger unit cell is obtained [2754(7), cf. 2616(3) ?3]; it is believed that this is a consequence of variable occupancy of the disordered solvent layers which lie parallel to bc between the ionic species.