Magnetic behavior in heterometallic one-dimensional chains or octanuclear complex regularly aligned with metal–metal bonds as –Rh–Rh–Pt–Cu–Pt

Abstract Heterometallic one-dimensional chains, [{Rh 2 (O 2 CCH 3 ) 4 }{Pt 2 Cu(piam) 4 (NH 3 ) 4 }] n (PF 6 ) 2 n ( 1 and 2 , piam = pivalamidate) and [{Rh 2 (O 2 CCH 3 ) 4 }{Pt 2 Cu(piam) 4 (NH 3 ) 4 } 2 ](CF 3 CO 2 ) 2 (ClO 4 ) 2 ·2H 2 O ( 3 ), are paramagnetic one-dimensional chains or octanuclear complexes that are either aligned as –Rh–Rh–Pt–Cu–Pt– ( 1 and 2 ) or as Pt–Cu–Pt–Rh–Rh–Pt–Cu–Pt ( 3 ) with metal–metal bonds. Compounds 1 – 3 have rare structures, from the standpoint of that the paramagnetic species of Cu atoms are linked by direct metal–metal bonds. Magnetic susceptibility measurements for 1 – 3 performed at temperatures of 2 K–300 K indicated that the unpaired electrons localize in the Cu 3d x 2 − y 2 orbitals, where S  = 1/2 Cu(II) atoms are weakly antiferromagnetically coupled with J  = −0.35 cm −1 ( 1 ), −0.47 cm −1 ( 2 ), and −0.45 cm −1 ( 3 ).