TY - JOUR
T1 - Early-and Late-Lanthanide Pyridinethiolates
T2 - Synthesis, Redox Stability, and Structure
AU - Berardini, M.
AU - Lee, Jongseong
AU - Freedman, Deborah
AU - Lee, Jae
AU - Emge, T. J.
AU - Brennan, J. G.
PY - 1997
Y1 - 1997
N2 - The early and late lanthanides form stable complexes with the pyridinethiolate (2-S-NC5H4, or SPy) ligands. The Ce compound Ce(SPy)3 is relatively insoluble in neutral organic donor solvents such as THF or pyridine but can be solubilized by the addition of [PEt4[SPy] to form the orange homoleptic cerium thiolate [PEt4][Ce(SPy)4] (1). Low-temperature structural characterization of 1 showed that the complex is isostructural with the known Eu(III) derivative. Further oxidation of Ce(III) with dipyridyl disulfide does not occur. Molecular 1 is colored due to a low-energy f1-to-d1 promotion. As the size of the lanthanide ion decreases, the solubility of neutral Ln(SPy)3 appears to increase. Colorless [PEt4][Ln(SPy)4] (Ln = Ho (2), Tm (3)) can also be isolated by fractional crystallization, and the compounds are isostructural with the Ce and Eu derivatives. The neutral complexes of Ho and Tm are also slightly soluble in acetonitrile and dimethoxyethane and very soluble in pyridine. Both divalent and bivalent Yb complexes of the pyridinethiolate ligand dissolve in and crystallize from pyridine. Divalent Yb(SPy)2 crystallizes as the pentagonal bipyramidal molecule (py)3Yb(SPy)2 (4). One pyridine nitrogen and the four donor atoms of the two pyridinethiolate ligands are bound in equatorial positions, and two neutral pyridine ligands occupy the axial sites. The Yb(III) compound crystallizes readily from pyridine as molecular 8-coordinate (py)2yYb(SPy)3 (5). Compounds 4 and 5 are intensely colored; 4 has a visible Yb(II)-to-pyridine charge transfer excitation that is virtually identical in energy to the analogous excitation in SmI2(py)4, while 5 has a visible S-to-Yb charge transfer absorption. Crystal data (Mo Kα, 153(5) K) are as follows: 1, monoclinic space group P2/n, a = 15.118(6) Å, b = 16.117(4) Å, c = 26.443(7) Å, β= 90.14(3)°, Z = 4; 4, monoclinic space group Cc, a = 10.588(1) Å, b = 16.810(3) Å, c = 14.833(5) Å, β= 109.12(2)°, Z = 4; 5, monoclinic space group P21/n, a = 9.672(2) Å, b = 16.293(4) Å, c = 19.214(3) Å, β= 101.51(2)°, Z = 4.
AB - The early and late lanthanides form stable complexes with the pyridinethiolate (2-S-NC5H4, or SPy) ligands. The Ce compound Ce(SPy)3 is relatively insoluble in neutral organic donor solvents such as THF or pyridine but can be solubilized by the addition of [PEt4[SPy] to form the orange homoleptic cerium thiolate [PEt4][Ce(SPy)4] (1). Low-temperature structural characterization of 1 showed that the complex is isostructural with the known Eu(III) derivative. Further oxidation of Ce(III) with dipyridyl disulfide does not occur. Molecular 1 is colored due to a low-energy f1-to-d1 promotion. As the size of the lanthanide ion decreases, the solubility of neutral Ln(SPy)3 appears to increase. Colorless [PEt4][Ln(SPy)4] (Ln = Ho (2), Tm (3)) can also be isolated by fractional crystallization, and the compounds are isostructural with the Ce and Eu derivatives. The neutral complexes of Ho and Tm are also slightly soluble in acetonitrile and dimethoxyethane and very soluble in pyridine. Both divalent and bivalent Yb complexes of the pyridinethiolate ligand dissolve in and crystallize from pyridine. Divalent Yb(SPy)2 crystallizes as the pentagonal bipyramidal molecule (py)3Yb(SPy)2 (4). One pyridine nitrogen and the four donor atoms of the two pyridinethiolate ligands are bound in equatorial positions, and two neutral pyridine ligands occupy the axial sites. The Yb(III) compound crystallizes readily from pyridine as molecular 8-coordinate (py)2yYb(SPy)3 (5). Compounds 4 and 5 are intensely colored; 4 has a visible Yb(II)-to-pyridine charge transfer excitation that is virtually identical in energy to the analogous excitation in SmI2(py)4, while 5 has a visible S-to-Yb charge transfer absorption. Crystal data (Mo Kα, 153(5) K) are as follows: 1, monoclinic space group P2/n, a = 15.118(6) Å, b = 16.117(4) Å, c = 26.443(7) Å, β= 90.14(3)°, Z = 4; 4, monoclinic space group Cc, a = 10.588(1) Å, b = 16.810(3) Å, c = 14.833(5) Å, β= 109.12(2)°, Z = 4; 5, monoclinic space group P21/n, a = 9.672(2) Å, b = 16.293(4) Å, c = 19.214(3) Å, β= 101.51(2)°, Z = 4.
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U2 - 10.1021/ic9706865
DO - 10.1021/ic9706865
M3 - Article
AN - SCOPUS:0000079870
SN - 0020-1669
VL - 36
SP - 5772
EP - 5776
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 25
ER -