Synthesis and structure of the first neutral octahedral cis-dioxorhenium(V) complex

The complex cis-[ReO2(Hdab)(py)(2)] (1) (H(2)dab = 1,2-diaminobenzene) has been prepared by reacting trans-[ReO2(py)(4)]I with H(2)dab in ethanol. Thi s is the first example of a neutral hexacoordinate rhenium(V) complex with a cis arrangement of the two oxo groups. The compound also provides the fir st example of a bidentate monoanionic monoimino coordination mode of H(2)da b. Crystal data for 1 . (H(2)dab)I .H2O: C22H26IN6O2Re .H2O, triclinic, spa ce group P (1) over bar, a = 9.570(2), b = 12.493(3), c = 12.851(3) Angstro m, alpha = 61.60(3), beta = 70.56(3), gamma = 78.68(4)degrees, V = 1273.1(4 ) Angstrom (3) and Z = 2. (C) 2001 Elsevier Science B.V. All rights reserve d.