Single-and double-decker lanthanide complexes with 1-methyltetrabenzooctadehydrocorrin were synthesized by reaction of 3-[(1-hydroxy-1-methyl-1H-isoindol-3-yl)methylidene]-2,3-dihydro-1H-isoindol-1-one with hydrazine hydrate in the presence of lanthanide acetates. Heating of the former with phthalonitrile gave unsymmetrical double-and triple-decker complexes containing 1-methyltetrabenzooctadehydrocorrin and phthalocyanine fragments. Spectral properties of the synthesized complexes were studied.Phthalocyanines and porphyrins constitute two most important classes of tetrapyrrole pigments [1-3]. These compounds are capable of coordinating many elements of the Periodic Table, including lanthanides, to form coordination compounds with various structures, both single-decker and sandwich-like [4]. The latter may be used as sensors [5][6][7], materials for ionizing radiation detectors [8], dyes for passive synchronization of laser modes [9], and electrochromic materials [10]. Among numerous sandwich-like complexes, mixed-ligand coordination compounds containing tetrabenzoporphyrin and phthalocyanine fragments were studied most poorly [11,12], whereas coordination compounds based on tetrabenzocorrins were not reported at all.The present work was aimed at synthesizing homoand heteroligand lanthanide complexes containing 1-methyltetrabenzooctadehydrocorrin and phthalocyanine fragments and studying their spectral properties. As reported previously [13], single-decker 1-methyltetrabenzooctadehydrocorrin complex I with hydroxylanthanum can be prepared by reaction of 3-[(1-hydroxy-1-methyl-1H-isoindol-3-yl)methylidene]-2,3-dihydro-1H-isoindol-1-one (II) with hydrazine hydrate in the presence of lanthanum(III) acetate in boiling butan-1-ol (reaction time 3 h). We applied a similar procedure to obtain analogous lutetium and erbium complexes III and IV. In addition, we found that the reaction performed with a deficiency of metal salt gives mainly double-decker bis(1-methyltetrabenzooctadehydrocorrin) complexes of lutetium, erbium, and lanthanum (compounds V-VII). Thus the synthesis of single-and double-decker lanthanide complexes with 1-methyltetrabenzooctadehydrocorrin may be illustrated by Scheme 1.When the reaction was complete, in each case the mixture was diluted with toluene. Most unreacted compound II and metal salt separated from the solution, while corrin metal complexes remained dissolved. The precipitate was filtered off, and the filtrate was subjected to column chromatography on aluminum oxide using toluene as eluent, the first bright green fraction being collected. We thus succeeded in separating the target metal complexes from by-products. Unlike initial compound II and products of its reaction with hydrazine (brown tarry substances), corrin metal complexes are readily soluble in toluene-butan-1-ol and are characterized by high chromatographic mobility on aluminum oxide (R f 0.70-0.85).Compounds I and III-VII were isolated as dark green crystalline substances that are readily soluble in toluene, acetone, DMF, and ch...