Synthesis of arenethiolate complexes of divalent and trivalent lanthanides from metallic lanthanides and diaryl disulfides: Crystal structures of [{Yb(hmpa)(3)}(2)(mu-SPh)(3)][SPh] and Ln(SPh)(3)(hmpa)(3) (Ln=Sm, Yb; hmpa=hexamethylphosphoric triamide)

A convenient and one-pot synthetic method of lanthamide thiolate was developed. An excess of metallic samarium, europium, and ytterbium directly reacted with diaryl disulfides in THF to give selectively Ln(II) thiolate complexes, [Ln(SAr)(mu-SAr)(thf)(3))(]2) (1, Ln = Sm; 2, Ln = Eu; Ar = 2,4,6-triisopropylphenyl), Yb(SAr)(2)(py)(4) (3, py = pyridine), and [{Ln(hmpa)(3)}(2)(mu-SPh)(3)][SPh] (6, Ln = Sm; 7, Ln = Eu; 8, Ln = Yb; hmpa = hexamethylphosphoric triamide). Reaction of metallic lanthanides with 3 equiv of disulfides afforded Ln(III) thiolate complexes, Ln(SAr)(3)(py)(n)(thf)(3-n) (9a, Ln = Sm, n = 3; 9b, Ln = Sm, n = 2; 10, Ln = Yb, n = 3) and Ln(SPh)3(hmpa)3 (11, Ln = Sm; 12, Ln = Eu; 13, Ln = Yb). Thus, Ln(II) and Ln(III) thiolate complexes were prepared from the same source by controlling the stoichiometry of the reactants. X-ray analysis of 8 revealed that 8 has the first ionic structure composed of triply bridged dinuclear cation and benezenethiolate anion [8, orthorhombic, space group P2(1)2(1)2(1) with a = 21.057(9), b = 25.963(7), c = 16.442(8) Angstrom, V = 8988(5) Angstrom(3), Z = 4, R = 0.040, R(w) = 0.039 for 5848 reflections with I > 3 sigma(I) and 865 parameters]. The monomeric structures of 11 and 13 were revealed by X-ray crystallographic studied [11, triclinic, space group P (1) over bar with a = 14.719(3), b = 17.989(2), c = 11.344(2) Angstrom, alpha = 97.91(1), beta = 110.30(2), gamma = 78.40(1)degrees, V = 2751.9(9) Angstrom(3), Z = 2, R = 0.045, R(w) = 0.041 for 7111 reflections with I > 3 sigma(I) and 536 parameters; 13, triclinic, space group P (1) over bar with a = 14.565(2), b = 17.961(2), c = 11.302(1) Angstrom, alpha = 97.72(1), beta = 110.49(1), gamma = 78.37(1)degrees, V = 2706.0(7) Angstrom(3), Z = 2, R = 0.031, R(w) = 0.035 for 9837 reflections with I > 3 sigma(I) and 536 parameters]. A comparison with the reported mononuclear and dinuclear lanthamide thiolate complexes has been made to indicate that the Ln-S bonds weakened by the coordination of HMA to lanthanide metals have ionic character.