454470-96-3Relevant articles and documents
Electronic structures of highly symmetrical compounds of f elements. 34 [1] Synthesis and spectroscopic characterization of biscyclohexylisocyanide adducts derived from the tris(bis(trimethylsilyl)amido)lanthanide(III) moiety as well as crystal, molecular, and electronic structure of the corresponding neodymium compound
Jank, Stefan,Hanss, Jan,Reddmann, Hauke,Amberger, Hanns-Dieter,Edelstein, Norman M.
, p. 1355 - 1365 (2008/10/08)
The reaction of tris(bis(trimethylsilyl)amido)lanthanide(III) (Ln(btmsa)3) with two equiv. of cyclohexylisocyanide gives good yields of complexes of composition Ln(btmsa)3(CNC6H11)2 (Ln = Y(1), La(2), Ce(3), Pr(4), Nd(5), Sm(6), Eu(7), Tb(8), Dy(9), Ho(10), Tm(11) and Yb(12)). Complex 5 crystallizes in the monoclinic space grouop C2/c with a = 25.689(8) A, b = 12.165(2) A, c = 17.895(15) A, β = 122.47 (2)°, V = 4718.07 A3, Z = 4 and R = 0.0342. The structure of compound 5 shows the five-coordinate Nd3+ ion in a nearly exact trigonal bipyramidal environment with two CNC6H11 molecules in the axial and the three btmsa ligands in the equatorial positions. The linear dichroism spectrum of a single crystal of complex 5 was measured at room temperature, and the absorption spectrum of powdered material at low temperatures. From the spectra obtained a truncated crystal field (CF) splitting pattern is derived, and simulated by fitting the parameters of a phenomenological Hamiltonian. For 80 assignments a reduced r.m.s, deviation of 20.7 cm-1 is achieved. Making use of the calculated wavefunctions and eigenvalues the experimentally determined temperature dependence of μ2eff could be reproduced by adopting an orbital reduction factor k = 0.991, and on the basis of the CF parameters used the experimentally oriented non-relativistic molecular orbital scheme of compound 5 is set up.
