44 https://doi.org/10.1107/S2056989021013025 Acta Cryst. (2022). E78, 44–46 research communications Received 29 November 2021 Accepted 7 December 2021 Edited by A. V. Yatsenko, Moscow State University, Russia Keywords: lanthanide; terbium; bis(cyclopenta- dienyl); (methoxyphenyliminomethyl)phenolate; salicylimino; crystal structure. CCDC reference: 2127087 Supporting information: this article has supporting information at journals.iucr.org/e Bis(g 5 -cyclopentadienyl)(2-{[(2-methoxyphenyl)- imino]methyl}phenolato-j 3 O,N,O 0 )terbium Mikhail E. Minyaev, a,b * Konstantin A. Lyssenko, c Dmitrii M. Roitershtein a,b and Ilya E. Nifant’ev c,b a N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninsky Prospect, Moscow, 119991, Russian Federation, b A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky prospect, Moscow, 119991, Russian Federation, and c Chemistry Department, M.V. Lomonosov Moscow State University, 1 Leninskie Gory, Str., Building 3, Moscow, 119991, Russian Federation. *Correspondence e-mail: mminyaev@ioc.ac.ru The air- and moisture-sensitive title compound, [Tb(C 5 H 5 ) 2 (C 14 H 12 NO 2 )], was synthesized from tris(cyclopentadienyl)(tetrahydrofuran)terbium and 2-{[(2- methoxyphenyl)imino]methyl}phenol. Each Tb atom is coordinated by two cyclopentadienyl ligands in an  5 -coordination mode and by one N and two O atoms of the organic ligand in a tridentate  3 O,N,O 0 -mode. 1. Chemical context Bis(cyclopentadienyl) complexes of rare-earth metals attract significant attention because of their important role in the development of organometallic chemistry of 4f elements (Schumann et al., 1995; Wedal & Evans, 2021; Evans, 2016). This type of complex is one of the first discovered organo- lanthanide classes (Maginn et al., 1963). The vigorous interest in cyclopentadienyl complexes for the chemistry of rare-earth elements is mainly due to the simpli- city of cyclopentadienyl ligand modification by replacing the hydrogen atoms of the five-membered ring with various organic fragments (Harder et al., 2013; Roitershtein, Puntus et al., 2018; Hou & Wakatsuki, 2002). Moreover, in the case of bis(cyclopentadienyl) derivatives such as (C 5 H 5 ) 2 LnX, the additional anionic ligand X  can be coordinated in a mono-, bi- or, as in the present case, a tridentate mode. Such a combination of ligands provides an extremely broad structural diversity for cyclopentadienyl derivatives (Edelmann & Poremba, 1997; Goodwin et al., 2018). This report describes the synthesis and crystal structure of bis( 5 -cyclopentadien- yl)(2-{[(2-methoxyphenyl)imino]methyl}phenolato)terbium, which is a product of the partial protonation of the tris- (cyclopentadienyl)terbium complex with 2-{[(2-methoxy- phenyl)imino]methyl}phenol (Fig. 1). ISSN 2056-9890