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Syntheses, Structural, and Spectroscopic Properties of Copper(II) Complexes of Constrained Macrocyclic Ligands
Author(s) -
Choi JongHa,
Joshi Tanmaya,
Spiccia Leone
Publication year - 2012
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.201100398
Subject(s) - crystallography , chemistry , copper , hydrogen bond , molecule , octahedron , oxygen atom , ligand (biochemistry) , macrocyclic ligand , crystal structure , oxygen , nitrogen , stereochemistry , receptor , organic chemistry , biochemistry
The complexes [Cu(L 1 )(H 2 O) 2 ](BF 4 ) 2 · 2H 2 O ( 1 ) [L 1 = 5, 16‐dimethyl‐2, 6, 13, 17‐tetraazatricyclo(14, 4, 0 1.18 ,0 7.12 )docosane] and 0.5[Cu(L 2 )(NO 3 ) 2 ][Cu(L 2 )](NO 3 ) 2 ( 2 ) [L 2 = dibenzyl‐5, 16‐dimethyl‐2, 6, 13, 17‐tetraazatricyclo(14, 4, 0 1.18 ,0 7.12 )docosane] were synthesized and characterized by single crystal X‐ray analyses. In these constrained macrocycles, the central copper(II) atoms are in a tetragonally distorted octahedral environment with four nitrogen atoms of the macrocyclic ligands in equatorial positions and oxygen atoms from either water molecules or nitrato groups in axial positions. The macrocyclic ligands in both complexes adopt the most stable trans ‐III conformation. The Cu–N distances [1.999(7)–2.095(7) Å] are typical for such complexes, but the axial ligands are weakly coordinating Cu–OH 2 bonds [2.693(3) Å] and Cu–ONO 2 bonds [2.873(7) Å] due to the combination of the pseudo Jahn–Teller effect and strong in‐plane ligand field. The crystals are stabilized by a three‐dimensional network by hydrogen bonds that are formed among the secondary nitrogen hydrogen atoms, oxygen atoms of water molecules, fluorine atoms of BF 4 – , and oxygen atoms of NO 3 – . The electronic absorption and IR spectroscopic properties are also discussed.