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New Homoleptic Rare Earth 3,5‐Diphenylpyrazolates and 3,5‐Di‐ tert ‐butylpyrazolates and a Noteworthy Structural Discontinuity
Author(s) -
Rad Nazli E.,
Junk Peter C.,
Deacon Glen B.,
Wang Jun
Publication year - 2019
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201900015
Subject(s) - homoleptic , chemistry , crystallography , denticity , ionic radius , metal , rare earth , dysprosium , chelation , lanthanide , stereochemistry , crystal structure , inorganic chemistry , ion , mineralogy , organic chemistry
Direct thermally induced reactions between rare earth metals ( Ln = Y,Ce, Dy, Ho, and Er) activated by Hg metal and 3,5‐diphenylpyrazole (Ph 2 pzH) or 3,5‐di‐ tert ‐butylpyrazole ( t Bu 2 pzH) yielded either homoleptic complexes [ Ln n ( R 2 pz) 3 n ] or a heteroleptic complex [ Ln (Ph 2 pz) 3 (Ph 2 pzH) 2 ] From Ph 2 pzH, [Ce 3 (Ph 2 pz) 9 ], [Dy 2 (Ph 2 pz) 6 ], [Ho 2 (Ph 2 pz) 6 ], and [Y(Ph 2 pz) 3 (Ph 2 pzH) 2 ] were isolated. The first has a bowed trinuclear Ce 3 backbone with two η 2 pyrazolate ligands on the terminal metal atoms and one on the middle, and bridging by both μ‐η 2 :η 2 and μ‐η 2 :η 5 ligands between the terminal and the central Ce atoms. Although both the Dy and Ho complexes are dinuclear, the former has the rare μ‐η 2 :η 1 bridging whilst the latter has μ‐η 2 :η 2 bridging. Thus the dysprosium complex is seven‐coordinate and the holmium is eight‐coordinate, in contrast to any correlation with Ln 3+ ionic radii, and the series has a remarkable structural discontinuity. The heteroleptic Y complex is eight coordinate with three chelating Ph 2 pz and two transoid unidentate Ph 2 pzH ligands. From t Bu 2 pzH, dimeric [ Ln 2 ( t Bu 2 pz) 4 ] ( Ln = Ce, Er) were isolated and are isomorphous with eight coordinate Ln atoms ligated by two chelating terminal t Bu 2 pz and two μ‐η 2 :η 2 t Bu 2 pz donor groups. They are also isomorphous with previously reported La, Nd, Yb, and Lu complexes.