Synthesis and characterization of a chiral molecule-based metamagnet made by a chiral triplet organic radical and transition metal ion

Crystals of {1.M(II)(hfac)(2)}(n) (M = Mn, Cu) were obtained by mixing the 1,3-bis(N-tert-butylamino-N-oxyl)-5-{1-methyl-1-((S)-2-methylbutoxy)ethyl}b enzene (1) and bis(hexafluoroacetylacetonato)M(II) {M(II).(hfac)(2)} in die thyl ether/n-heptane. A single crystal of {1.Mn(II)(hfac)(2)}(n) is triclin ic, space group P1 (No. 1), with a = 11.0005(3) Angstrom, b = 11.8183(4) An gstrom. c = 17.7135(7) Angstrom, alpha = 81.607(3)degrees, beta = 84.801(3) degrees, gamma = 63.516(2)degrees, V = 2038.3(1) Angstrom(3), and D-x = 1.3 80 g/cm(3) for Z = 1. A single crystal of {1.Cu(II)(hfac)(2)}(n) is triclin ic, space group P1 (No. 1), with a = 11.2831(7) Angstrom, b = 11.5615(7) An gstrom, c = 18.0163(9) Angstrom, alpha = 82.384(4)degrees, beta = 74.242(4) degrees, gamma = 61.826(5)degrees, V = 1993.9(2) Angstrom(3), and D-x = 1.4 3 g/cm(3) for Z = 1. An X-ray crystal structure analysis revealed the forma tion of a helical one-dimensional polymeric structure. It not only contains a (S) chiral carbon center but also (R) C2 chiral skeleton of the 1,3-bis( N-tert-butylamino-N-oxyl)benzene moiety. Each of the two aminoxyl radical c enters are coupled ferromagnetically within the organic radical molecule an d is coupled antiferromagnetically to the d(5) manganese(II) ions. The temp erature dependence of the magnetization revealed that the heterospin system behaves as a metamagnet below 5.4 K.