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Dinuclear Zinc Complexes Supported by Macrobinucleating Hexaaza‐Dithiophenolate Macrocycles: Synthesis of Zinc Thiolate Complexes with Biologically Relevant N 3 S and N 2 SCl Donor Sets
Author(s) -
Lehmann Ulrike,
Kersting Berthold
Publication year - 2013
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.201300074
Subject(s) - chemistry , zinc , chelation , crystallography , stereochemistry , diethylenetriamine , nuclear magnetic resonance spectroscopy , ring (chemistry) , inorganic chemistry , organic chemistry
Abstract The ability of the macrocyclic hexaaza‐dithiophenolate macrocycles (H 2 L H6 , H 2 L Me2H4 , and H 2 L Me6 ) to support dinuclear zinc complexes has been examined. The macrocyclces contain two 4‐ tert ‐butylthiophenolate units which are connected by two lateral dipropylenetriamine units with different nature and patterns (secondary or tertiary) of the N donors (H 2 L H6 : 6 × R 2 NH, H 2 L Me2H4 : 4 × R 2 NH, 2 × R 2 NMe, H 2 L Me6 : 6 × R 2 NMe). Three binuclear complexes ([Zn 2 (L H6 )] 2+ ( 1 ), [Zn 2 (L Me2H4 )] 2+ ( 2 ), and [Zn 2 H 2 (L Me6 )Cl 2 ] 2+ ( 3 )) were obtained, isolated as ClO 4 – or BPh 4 – salts, and characterized by CHN, ESI‐MS, IR, and NMR spectroscopy, and X‐ray crystallography ( 1( ClO 4 ) 2 , 1 (BPh 4 ) 2 , 2( BPh 4 ) 2 , 3 (ClO 4 ) 2 ). In contrast to the parent N 6 S 2 macrocycles with diethylenetriamine linkers which support bioctahedral [Zn 2 L(L′)] n + complexes (L' = bridging coligand), the present ligands coordinate to zinc with non‐bridging thiolato donors to afford tetrahedral ZnN 3 S ( 1 , 2 ) or ZnN 2 SCl ( 3 ) coordination environments. The decrease of the coordination number from 6 in the [Zn 2 L(L′)] n + to 4 in the present complexes is attributed to the change of the chelate‐ring size. The six‐membered chelate rings in 1–3 allow larger bond angles and encourage tetrahedral coordination.