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Synthesis of a New Potentially Hemilabile Ligand: 1‐[2‐(Diphenylphosphanyl)ethyl]‐3,5‐dimethylpyrazole, and Comparison of Its Bonding Properties with the Related 1‐[2‐(Ethylamino)ethyl]‐3,5‐dimethylpyrazole Ligand toward Rh I
Author(s) -
Esquius Glòria,
Pons Josefina,
Yáñez Ramón,
Ros Josep,
Mathieu René,
Donnadieu Bruno,
Lugan Noël
Publication year - 2002
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 - 10.1002/1099-0682(200211)2002:11<2999::aid-ejic2999>3.0.co;2-a
Subject(s) - chemistry , ligand (biochemistry) , denticity , carbon monoxide , medicinal chemistry , rhodium , stereochemistry , catalysis , crystal structure , crystallography , organic chemistry , receptor , biochemistry
The new ligand 1‐[2‐(diphenylphosphanyl)ethyl]‐3,5‐dimethylpyrazole ( 2 ) has been prepared by the reaction of 1‐(chloroethyl)‐3,5‐dimethylpyrazole and PPh 2 Li. The bidentate N,N ligand 1‐[2‐(ethylamino)ethyl]‐3,5‐dimethylpyrazole ( 1 ) and 2 react with [Rh(COD)(THF) 2 ][BF 4 ] to give [Rh(COD)( 1 )][BF 4 ] ( 3 ) and [Rh(COD)( 2 )][BF 4 ] ( 4 ), respectively. Substitution of 1,5‐cyclooctadiene with carbon monoxide in the latter complexes generates [Rh(CO) 2 ( 1 )][BF 4 ] ( 5 ) and [Rh(CO) 2 ( 2 )][BF 4 ] ( 6 ), respectively. Treatment of [Rh(COD)(THF) 2 ][BF 4 ] with two equivalent amounts of 2 results in the complex [Rh( 2 ) 2 ][BF 4 ] ( 7 ), which converts to [Rh(CO)( 2 ) 2 ][BF 4 ] ( 8 ) on reaction with carbon monoxide. Ligand 2 in complex 8 exhibits a hemilabile character. The single‐crystal X‐ray structures of 3 , 4 , and 7 are reported. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)