Rh(III) Porphyrins as Building Blocks for Porphyrin Coordination Arrays: From Dimers to Heterometallic Undecamers
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- 作者：James E. Redman ; Neil Feeder ; Simon J. Teat ; and Jeremy K. M. Sanders
- 刊名：Inorganic Chemistry
- 出版年：2001
- 出版时间：May 21, 2001
- 年：2001
- 卷：40
- 期：11
- 页码：2486 - 2499
- 全文大小：260K
- 年卷期：v.40,no.11(May 21, 2001)
- ISSN：1520-510X
文摘
The coordination chemistry of a Rh(III) porphyrin building block was investigated with a view to the constructionof heterometallic arrays of porphyrins. The Rh(III) porphyrin was found to coordinate methanol in the solid stateand weakly in CDCl3 solution. Crystallization afforded five coordinate 
stacked Rh(III) porphyrins. The distributionof products from reaction of Rh(III) porphyrin with DABCO, 4,4'-bipyridine, and 4,4'-bipyrimidine could bedisplaced toward dimeric species by silica gel column chromatography or recrystallization which served to removeexcess ligand. Weak coordination to nitriles was observed, although it was sufficiently strong to organize a dimericcomplex of 5,5'-dicyano-2,2'-bipyridine in the solid state. Complexes with 4,4'-bipyrimidine and 5,5'-dicyano-2,2'-bipyridine possess uncoordinated chelating nitrogen atoms. Larger heterometallic porphyrin arrays wereassembled using a combination of Sn(IV) and Rh(III) porphyrin coordination chemistry. A Sn(IV) porphyrinacted as a core around which were coordinated two isonicotinate groups, carboxylic acid functionalized porphyrins,or porphyrin trimer dendrons. Rh(III) porphyrins were coordinated to pyridyl groups at the periphery of theseentities. In this way an eleven porphyrin array, with four different porphyrin metalation states, was assembled.The diamagnetic nature of both the Rh(III) and Sn(IV) porphyrins, the slow ligand exchange kinetics on theNMR time scale, and tight ligand binding permitted the porphyrin arrays to be analyzed by two-dimensional 1HNMR techniques.
stacked Rh(III) porphyrins. The distributionof products from reaction of Rh(III) porphyrin with DABCO, 4,4'-bipyridine, and 4,4'-bipyrimidine could bedisplaced toward dimeric species by silica gel column chromatography or recrystallization which served to removeexcess ligand. Weak coordination to nitriles was observed, although it was sufficiently strong to organize a dimericcomplex of 5,5'-dicyano-2,2'-bipyridine in the solid state. Complexes with 4,4'-bipyrimidine and 5,5'-dicyano-2,2'-bipyridine possess uncoordinated chelating nitrogen atoms. Larger heterometallic porphyrin arrays wereassembled using a combination of Sn(IV) and Rh(III) porphyrin coordination chemistry. A Sn(IV) porphyrinacted as a core around which were coordinated two isonicotinate groups, carboxylic acid functionalized porphyrins,or porphyrin trimer dendrons. Rh(III) porphyrins were coordinated to pyridyl groups at the periphery of theseentities. In this way an eleven porphyrin array, with four different porphyrin metalation states, was assembled.The diamagnetic nature of both the Rh(III) and Sn(IV) porphyrins, the slow ligand exchange kinetics on theNMR time scale, and tight ligand binding permitted the porphyrin arrays to be analyzed by two-dimensional 1HNMR techniques.