Reaction of methanol ligated manganese(II) silanethiolate with pyridine related ligands – Different structures of complexes with MnNO 2 S 2 kernel Anna Kropidłowska, Jarosław Chojnacki, Barbara Becker * Department of Inorganic Chemistry, Chemical Faculty, Gdan ´ sk University of Technology, Narutowicza Str. 11/12, PL80-952 Gdan ´ sk, Poland Received 23 July 2006; received in revised form 15 October 2006; accepted 29 November 2006 Available online 6 December 2006 Abstract The reaction of [Mn{SSi(OBu t ) 3 } 2 (MeOH) 4 ] with pyridine and its three monosubstituted methyl derivatives leads to the formation of two distinct types of complexes, although both with the MnO 2 NS 2 kernel. The first two compounds (with pyridine or 2-picoline) contain two silanethiolate ligands, heterocyclic base and two methanol molecules. In the second case (3- and 4-picoline) the role of O-donor and simultaneously S-donor ligand is fulfilled by tri-tert-butoxysilanethiolate rest which under favorable conditions can serve as a chelating agent. Ó 2006 Elsevier B.V. All rights reserved. Keywords: Manganese; Complexes; Silanethiolates; Methanol as ligand; Pyridine; Picoline 1. Introduction Alcohol ligated transition metal thiolate complexes are rare and these incorporating heterocyclic N-donor ligands are really unique [1]. During the search of models for cat- alytic ZnðN his ÞðO ROH ÞðS cys Þ 2 site of liver alcohol dehydro- genase two such zinc based type of complexes were prepared using either N,O-chelate [2] or N,S,S-tripodal ligands [3,4] with the latter being a ionic compound. It is generally accepted that the lability of O-donor ligand and the bridging tendency of thiolate sulfur make the prepara- tion of such complexes difficult. Some of our investigations, focused on silanethiolate complexes obtained using bulky and hydrolytically stable ligand derived from tri-tert-butoxysilanethiol ðBu t OÞ 3 SiSH [5], approach this problem. We reported the prepara- tion of heteroleptic silanethiolates incorporating ammonia and pyridine-related coligands, e.g., ½MfSSiðOBu t Þ 3 g 2 ðNH 3 Þð2-MePyÞ (M = Zn, Co) [6,7]. We also observed the formation of ½CofSSiðOBu t Þ 3 g 2 ðLÞð2-MePyÞ com- plexes containing water (L = H 2 O) or methanol (L = MeOH) [7], but we were unable to isolate these spe- cies. Very recently we described the preparation and molec- ular structure of a hexacoordinated heteroleptic manganese(II) silanethiolate complex containing four methanol molecules as coligands – ½MnfSSiðOBu t Þ 3 g 2 ðMeOHÞ 4  (1) [8]. Its reaction with phenanthroline in meth- anol gave the pentacoordinated ½MnfSSiðOBu t Þ 3 g 2 ðphenÞðMeOHÞ complex (MnN 2 OS 2 core) where the ligat- ing alcohol is able to reversibly enter and leave the manga- nese coordination sphere [9]. When 1 was allowed to react with imidazole or its methyl derivatives, one of the obtained products was a N–HS hydrogen bonded assembly of two complexes – ½MnfSSiðOBu t Þ 3 g 2 - ð2-MeImidÞ and ½MnfSSiðOBu t Þ 3 g 2 ð2-MeImidÞðMeOHÞ 2  [10]. According to our best knowledge, the last one, with MnNOS 2 kernel, represents a sole example of a neutral complex featuring the set of four independent ligands – two thiolates, alcohol and heterocyclic base – somewhat 0020-1693/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.ica.2006.11.025 * Corresponding author. Tel.: +48 58 3472592; fax: +48 58 3472694. E-mail address: bbecker@chem.pg.gda.pl (B. Becker). www.elsevier.com/locate/ica Inorganica Chimica Acta 360 (2007) 2363–2367