SYNTHESIS, STRUCTURE AND MAGNETIC-PROPERTIES OF TRANSITION-METAL COMPLEXES OF THE NITROXIDE HYL-SPIRO-[4,5-DIAZAFLUORENE-9,2'-IMIDAZOL]-1-OXYL

With the radical hyl-spiro-[4,5-diazafluorene-9,2'-imidazol]-1-oxyl L a series of transition metal complexes has been prepared: [ML3](SbF6)( 2) . 4H(2)O with M2+ = Mn2+ (1), Fe2+ (2), Co2+ (3), Ni2+ (4), Zn2+ (5 ). Reaction of L with Cu2+ in methanol yielded different products depe nding on the counterion. In the presence of weakly coordinating anions the Cu(I) complexes [Cu2L3](SbF6)(2) . H2O (6), [Cu2L3](OTf)(2) . 2Me OH (7) and [Cu2L3](ClO4)(2) (8) were formed. Stronger coordinating cou nter ions gave the complexes CuL2Cl2 . H2O (9), CuL2Br2 . H2O (10) and CuL2(NO3)(2) (11). Also the synthesis of [Ag2L3](SbF6)(2) . 2H(2)O (1 2), Pd(L)Cl-2 . H2O (13), Pt(L)Cl-2 . H2O (14), Ni(L)Cl-2, (15a), Ni(L )Cl-2 . 4H(2)O (15b) and [Ru(bipy)(2) .(L)]Cl-2 . 4H(2)O (16) is repor ted. The magnetic moments of 1-6 and 10 correspond in the range 200-30 0 K to those expected for noninteracting spins of the metal ion arid t he radicals. At low temperatures spin pairing of metal and radical spi ns is observed for 1-3. (C) 1998 Elsevier Science Ltd. All rights rese rved.