EUROPIUM PYRIDINETHIOLATES - SYNTHESIS, STRUCTURE, AND THERMOLYSIS

The transmetalation reaction of Hg(SPy)(2) (SPy = S-2-NC5H4) with Eu in pyridine gives the europium(II) pyridinethiolate coordination complex (py)(4)Eu(SPy)(2) (1) in 96% isolated yield. The reaction of 1 with BIPY in THF results in displacement of the pyridine ligands and the formation of the divalent coordination complex (BIPY)(TI-IF),Eu(SPy)2 (2). Low-temperature single-crystal X-ray diffraction experiments show that 1 and 2 are molecular 8 coordinate compounds. They are both intensely colored due to the presence of a visible europium-to-pyridine or europium-to-BTPY charge transfer (CT) absorption band. Trivalent [PEt(4)][Eu(SPy)(4)] (3) was prepared from the reaction of Eu/Hg amalgam with PySSPy in the presence of [PEt(4)][SPy]. X-ray diffraction analysis of 3 shows that all the pyridinechalcogenolate ligands are chelating the Eu(III) ion and there are three different eight coordinate isomers within the unit cell. Compound 3 is intensely colored because of a visible S-to-Eu CT absorption. At 500 degrees C, 3 decomposes to give EuS and a mixture of PySSPy, PySPy, EtSPy, and SPEt(3). Crystal data (Mo Ka, 153(5) K): 1, orthorhombic space group Pna2/1, a = 19.006(2) Angstrom, b = 9.724(5) Angstrom, c 15.592(5) Angstrom, z = 4; 2, monoclinic space group Cc, a 9.851(2) Angstrom, b = 16.817(3) Angstrom, c = 17.271(2) Angstrom, beta = 92.67(2)degrees, Z = 4; 3, monoclinic space group P2(1)/n, a = 15.043(3) Angstrom, b = 16.036(6) Angstrom, c 26.444(5) Angstrom, beta = 90.54(2)degrees, Z = 4.