ISSN:
0170-2041
Keywords:
Tetrapyrrole Ligands
;
Sandwich complexes
;
Porphyrin ligands
;
Schiff bases
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Metal Complexes with Tetrapyrrole Ligands, LX. - Pseudo Sandwich Complexes: Complexes of Metal(III) and -(IV) Ions with Porphyrin and Schiff-Base LigandsThe synthesis of novel metal complexes with a porphyrinate, (P)2-2), and an ethylenebis(salicylidenealdiminate) or similar tetradentate open chelate, (L-4)2-, as ligands is described. Their general formula [M(P)(L-4)]n is realized with n = o and M = ZrIV or HfIV or n = -1 with M = YIII or TbIII; in the latter, an additional Li+ ion warrants electroneutrality. These complexes are prepared from the metal monoporphyrinates MIV(P)X2 or MIII(P)X (X = acetylacetonate) and the corresponding Schiff-base derivatives, H2(L-4) or Li2(L-4), respectively. 1H-NMR data prove the square antiprismatic configuration of the ZrIV species at 295 K which is abandoned at 373 K when the (P)2- and (L-4)2- freely rotate about each other. Electrochemical measurements show that oxidations and reductions involve only the porphyrin ligands. The redox potentials experience shifts that can be understood in terms of the Hammett parameters σ of the substituents at (L-4)2-.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1991199101202
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