COMPLETION OF THE SERIES OF PT-2(ARNC(H)NAR)(4)(N), N=0, N=-PT SIGMA-BOND ORDERS OF 0, 1(1, N=+2, COMPOUNDS, WITH PT)2, 1, RESPECTIVELY/

The diplatinum compound Pt-2(DPhF)(4)Cl-2 (I) (DPhF = N,N'-diphenylfor mamidinate) has been synthesized by reacting Pt-2(OAc)(4)Cl-2 with HDP hF in a molten mixture. Reduction occurs in a similar reaction of the water-containing diplatinum compound [Pt-2(OAc)(4)(H2O)(2)](CF3SO3)(2) and molten N,N'-di-p-tolylformamidine, (HDTolF) which gives [Pt-2(DTo lF)(4)]OAc (II . H2O). The X-ray crystal structure has been determined for I . THF. Crystal data are as follows: orthorhombic, Pnnb with a = 18.747(3), b = 22.026(4), c = 12.685(4) Angstrom, V = 5238(2) Angstro m(3), Z = 4. This completes the first structurally characterized serie s of platinum compounds in the framework of four formamidinate groups bridging two metal atoms, where the metal-metal bond order goes from 0 to 1/2 to 1. The Pt(111) centers are separated by a distance of 2.516 9(7) Angstrom, the shortest distance in the series as predicted by bon ding considerations. (C) 1997 Elsevier Science S.A.