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Spectral, Structural, and Electrochemical Properties of Ruthenium Porphyrin Diaryl and Aryl(alkoxycarbonyl) Carbene Complexes: Influence of Carbene Substituents, Porphyrin Substituents, and trans ‐Axial Ligands
Author(s) -
Li Yan,
Huang JieSheng,
Xu GuoBao,
Zhu Nianyong,
Zhou ZhongYuan,
Che ChiMing,
Wong KwokYin
Publication year - 2004
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.200305758
Subject(s) - carbene , chemistry , porphyrin , ruthenium , dichloromethane , medicinal chemistry , aryl , stereochemistry , catalysis , photochemistry , organic chemistry , alkyl , solvent
Abstract A wide variety of ruthenium porphyrin carbene complexes, including [Ru(tpfpp)(CR 1 R 2 )] (CR 1 R 2 = C( p ‐C 6 H 4 Cl) 2 1 b , C( p ‐C 6 H 4 Me) 2 1 c , C( p ‐C 6 H 4 OMe) 2 1 d , C(CO 2 Me) 2 1 e , C( p ‐C 6 H 4 NO 2 )CO 2 Me 1 f , C( p ‐C 6 H 4 OMe)CO 2 Me 1 g , C(CHCHPh)CO 2 CH 2 (CHCH) 2 CH 3 1 h ), [Ru(por)(CPh 2 )] (por=tdcpp 2 a , 4‐Br‐tpp 2 b , 4‐Cl‐tpp 2 c , 4‐F‐tpp 2 d , tpp 2 e , ttp 2 f , 4‐MeO‐tpp 2 g , tmp 2 h , 3,4,5‐MeO‐tpp 2 i ), [Ru(por){C(Ph)CO 2 Et}] (por=tdcpp 2 j , tmp 2 k ), [Ru(tpfpp)(CPh 2 )(L)] (L = MeOH 3 a , EtSH 3 b , Et 2 S 3 c , MeIm 3 d , OPPh 3 3 e , py 3 f ), and [Ru(tpfpp){C(Ph)CO 2 R}(MeOH)] (R = CH 2 CHCH 2 4 a , Me 4 b , Et 4 c ), were prepared from the reactions of [Ru(por)(CO)] with diazo compounds N 2 CR 1 R 2 in dichloromethane and, for 3 and 4 , by further treatment with reagents L. A similar reaction of [Os(tpfpp)(CO)] with N 2 CPh 2 in dichloromethane followed by treatment with MeIm gave [Os(tpfpp)(CPh 2 )(MeIm)] ( 3 d ‐Os). All these complexes were characterized by 1 H NMR, 13 C NMR, and UV/Vis spectroscopy, mass spectrometry, and elemental analyses. X‐ray crystal structure determinations of 1 d , 2 a , i , 3 a , b , d , e , 4 a – c , and 3 d ‐Os revealed RuC distances of 1.806(3)–1.876(3) Å and an OsC distance of 1.902(3) Å. The structure of 1 d in the solid state features a unique “bridging” carbene ligand, which results in the formation of a one‐dimensional coordination polymer. Cyclic voltammograms of 1 a – c , g , 2 a – d , g – k , 3 b – d , 4 a , b , and 3 d ‐Os show a reversible oxidation couple with E 1/2 values in the range of 0.06–0.65 V (vs Cp 2 Fe +/0 ) that is attributable to a metal‐centered oxidation. The influence of carbene substituents, porphyrin substituents, and trans ‐ligands on the RuC bond was examined through comparison of the chemical shifts of the pyrrolic protons in the porphyrin macrocycles ( 1 H NMR) and the MC carbon atoms ( 13 C NMR), the potentials of the metal‐centered oxidation couples, and the RuC distances among the various ruthenium porphyrin carbene complexes. A direct comparison among iron, ruthenium, and osmium porphyrin carbene complexes is made.