SYNTHESIS, STRUCTURAL, AND EPR INVESTIGAT IONS ON FE-57 ENRICHED (1,1-DICYANOETHENE-2,2-DITHIOLATO)NITROSYLIRON(I), (N-BU4N)(2)[FE-57(NO)(I-MNT)(2)]

The molecular structure and X-as well as Q-band EPR studies of s(1,1-d icyanoethene-2,2-dithiolato)nitrosyliron(I) enriched with Fe-57 are re ported. (n-Bu4N)(2)[Fe(NO)(i-mnt)(2)] crystallizes triclinically, spac e group P (1) over bar with a = 9,5147(7) Angstrom, b = 10,4841(8) Ang strom, c = 25,840(2) Angstrom, alpha = 92,510(1)degrees, beta =_92,895 (1)degrees, gamma = 111,156(1)degrees, Z = 2. The g and the hyperfine coupling tensors A(N) and A(Fe) derived from the EPR spectra are rhomb ically-symmetric: g(1) = 2,043, g(2) = 2,039, g(3) = 2,031, A(1)(N) = 13,8.10(-4)cm(-1), A(2)(N) = 11,6.10(-4)cm(-1), A(3)(N) = 15,2.10(-4)c m(-1), A(1)(Fe) = 11,410-4cm(-1), A(2)(Fe) = 15,7.10(-4)cm(-1) and A(3 )(Fe) = 2,6.10(-4)cm(-1). The spin-density distribution within the fir st coordination sphere is discussed.