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Ga–Ga Bonds as Key Building Blocks for the Formation of Supramolecular Entities – Unusual Macrocyclic Tetra‐ and Octagallium Compounds
Author(s) -
Uhl Werner,
Stefaniak Christina,
Layh Marcus
Publication year - 2017
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201700144
Subject(s) - chemistry , carboxylate , crystallography , supramolecular chemistry , stereochemistry , tetra , metal , crystal structure , organic chemistry , medicinal chemistry
Treatment of the digallium compound R 2 Ga–GaR 2 ( 1 ) [R = CH(SiMe 3 ) 2 ] with the dicarboxylic acids 1,2‐ and 1,4‐(HO 2 CCH 2 O) 2 C 6 H 4 afforded, by the release of H 2 C(SiMe 3 ) 2 , macrocyclic compounds 2a and 2c , in which two organic spacer ligands connect two metal–metal bonds. Two CO 2 groups bridge each Ga–Ga bond, and different structures resulted with a parallel or perpendicular arrangement of the bridging ligands. The resorcinol derivative 1,3‐(HO 2 CCH 2 O) 2 C 6 H 4 yielded the unique compound 2b , in which four Ga–Ga bonds are bridged by four spacer ligands. The organic groups form loops, which are alternately arranged above and below the molecular plane with four saddle points and a structure approaching 4 symmetry. The 1,2‐ and 1,4‐diacids afforded tetrakis(digallium) compounds 3a and 3c in the presence of water. In both cases carboxylate groups and hydroxido ligands bridge two Ga atoms of two different Ga–Ga bonds. The spacer ligands connect two of these fragments and adopt parallel orientations to form molecular boxes. Again, the 1,3‐diacid afforded a unique structural motif in which a Ga 4 O 6 skeleton (two Ga–Ga bonds) is bridged by a single organic spacer, reminiscent of the handle of a basket.