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Syntheses, Structures, and Solution Studies of Multicomponent Macrocycles and Cages Based on Versatile Ligands
Author(s) -
Zhang YingYing,
Gao WenXi,
Lin YueJian,
Mi LiWei,
Jin GuoXin
Publication year - 2017
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201702244
Subject(s) - pyrazine , chemistry , ligand (biochemistry) , denticity , palladium , crystallography , chelation , stereochemistry , metal , rhodium , acceptor , combinatorial chemistry , inorganic chemistry , organic chemistry , crystal structure , biochemistry , receptor , physics , condensed matter physics , catalysis
Different types of multinuclear half‐sandwich rhodium macrocycles and cages were designed and synthesized by using two similar multifunctional hydroxamate ligands (pyrazine‐2‐hydroxamic acid (NaH L 1 ) and 4,4′‐bipyridine‐2‐hydroxamic acid (KH L 2 )) featuring one monodentate site and two pairs of chelating sites. The Rh III –Pd II heterometallic macrocycles were constructed by using the semi‐open palladium(II) source [Pd(en)Cl 2 ] with two free acceptor sites. However, only one kind of macrocycle was found when the shorter ligand L 1 was used, while in for the larger ligand, various spectroscopic techniques demonstrated the coexistence of hexanuclear and octanuclear macrocycles in solution and the proportions of both components depended on concentration and temperature. The palladium salt Pd(NO 3 ) 2 , as a source of “naked” Pd 2+ , was introduced to assemble the cuboid‐shaped cage composed of two types of metal ions and three types of organic ligands. In addition, two silver(I)‐containing mixed‐metal complexes bridged by pyrazine were obtained, in which two forms of decanuclear complex with C 2 v and C 2 h point symmetry cocrystallized—one is a polymeric structure and the other is a discrete cage. However, the third form, with D 2 point symmetry, was found in the larger cage.