CRYSTAL AND MOLECULAR-STRUCTURE OF MN[(OPPH2)(2)N](3)CENTER-DOT-CH2CL2, A NEW MONOMERIC MANGANESE(III) COMPLEX STABILIZED BY OXYGEN CHELATING LIGANDS

The reaction between [Mn(CO)(5)]Br and Na[(OPPh2)(2)N] in argon atmosp here affords the preparation of Mn(CO)(4)[(OPPh2)(2)N] as a white powd er. During attempts to grow X-ray diffraction quality crystals the tet racarbonylmanaganese (I) complex was oxidized and deep purplish-blue: crystals were isolated. An Xray diffractometry analysis has revealed t he identity of the new product, i.e. the manganese(III) derivative, Mn [(OPPh2)(2)N](3). CH2Cl2. The compound crystallizes in the triclinic s pace group P-1 and the crystal contains discrete, monomeric molecules of Mn[(OPPh2)(2)N](3). The imidodiphosphinato groups are coordinated t hrough both oxygen atoms of a ligand moiety to the central manganese a tom. The resulted coordination octahedron exhibits;a tetragonally elon gated distortion as reflected by the Mn-O bond lengths [av. 2.130(16), 1.945(6) Angstrom] and cia O-Mn-O bond angles [endocyclic (av.) 90.5( 0.6)degrees; exocyclic (range) 87.2(0.1)-92.7(0.1)degrees]. The struct ure of the title compound is compared with those of other monomeric ma nganese(III) derivatives containing MnO6 cores with various degrees of distortion. (C) 1998. Elsevier Science Ltd. All rights reserved.