The solid-state, solution and gasephase interactions of diphosphane monooxide spacers with heavier group 8,9 transition metals and gallium in novel organometallic assemblies: An experimental and computational study Kirill Yu. Monakhov a, * ,1 , Elena V. Grachova b, * , Galina L. Starova b , Thomas Zessin a , Gerald Linti a a Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany b Department of Chemistry, St. Petersburg State University, Universitetskii pr. 26,198504 St. Petersburg, Russia article info Article history: Received 10 December 2011 Received in revised form 22 February 2012 Accepted 3 March 2012 Keywords: Transition metals Gallium Spacer Crystal structures Density functional calculations abstract Six new mono-substituted carbonyl clusters [M 3 (CO) 11 (DPMO)] (M ¼ Os, Ru; 1e4) and [Rh 6 (CO) 15 (DPMO)] (5, 6) were obtained from the reactions of non-symmetrical bifunctional diphos- phane monoxides (DPMOs, Ph 2 P(CH 2 ) n P(O)Ph 2 , n ¼ 2, 3) with triangular clusters [Os 3 (CO) 12 ] and [Ru 3 (CO) 12 ], and octahedral cluster [Rh 6 (CO) 15 (NCMe)] under mild conditions. 1e6 were then subjected to electrophilic reactions with GaCl 3 , which resulted in coordination-based molecular assemblies [M 3 (CO) 11 (DPMO)(GaCl 3 )] (M ¼ Ru, Os; 7e10) and [Rh 6 (CO) 15 (DPMO)(GaCl 3 )] (11 , 12). 1e12 were char- acterised by 31 P{ 1 H} NMR, IR spectroscopy, and FAB mass spectrometry. The crystal structures of 1 , 2 and 7 were determined by single-crystal X-ray analysis. 7 is the first solid-state characterised OseGa bridged complex. The latter and its constitutive fragment, 1 , were studied by density functional calculations in the gas phase and in solution in order to better understand their structural features. Two different rotameric structures related by rotation about the PeCeCeP linkage of the DPMO ligand were established for 1 and 7 . The bonding properties of 7 were analysed by means of a quantitative energy decomposition analysis (EDA). The EDA revealed a predominant electrostatic character for the interactions between the three units (carbonyl cluster, gallium halide and spacer) constitutive of 7 . Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction Coordination-based molecular assemblies with well-defined composition, specific properties and structures containing both main group elements and transition metals in different oxidation states attract considerable attention stimulated by purely academic and practical reasons. Their synthesis, structural characterisation and studies at the computational level are of high current interest in diverse branches of chemical science. Herein, we focus on organometallic complexes in which bridging ligands link metal centres of dramatically different nature. Such assemblies seem to have a good chance to display unusual physicochemical properties, catalytic properties [1] and to be precursors to a wide range of hybrid materials [2]. What types of constitutive molecular units were used to fabri- cate novel multifunctional coordination-based assemblies? The definite size, chemical properties, and structural features of tran- sition metal (TM) carbonyl clusters give the possibility to use the latter as versatile building blocks for the synthesis of complicated macromolecules [3] and metal nanoparticles [4]. The Lewis acidic main group metal salt can form coordination complexes with electron-rich ligands. In its turn, an organic linker (or spacer) with two coordination sites at the beginning and at the end of the ligand chain makes use of the opportunity to link metal centres of two different species. Thus, molecular architectures can be constructed by design of such a relevant spacer. The aim of this work is to explore new coordination-based molecular assemblies based on non-symmetrical bifunctional phosphanes DPMOs of the type Ph 2 P(CH 2 ) n P(O)Ph 2 (n ¼ 2, 3) linking low-nuclear carbonyl clusters of the heavier group 8 and 9 transition metals (Ru, Os and Rh), namely [M 3 (CO) 12 ] (M ¼ Ru, Os) and [M 6 (CO) 16 ] (M ¼ Rh) and the group 13 element halide, GaCl 3 . The choice of the spacers was dictated by the nature of both hetero- metallic centres. While the soft phosphane P-donors are usually bonded to the d-metals, the hard phosphane oxide O-donors are ideal to connect the group 13 metals [5e7]. It is also noteworthy that the structural chemistry of the organometallic TM VIII eGa (TM ¼ Ru, Os) and TM Ix eGa (TM ¼ Rh, Ir) * Corresponding authors. Tel.: þ7 (812) 428 4028; fax: þ7 (812) 428 6939. E-mail addresses: monakhov@unistra.fr (K.Yu. Monakhov), bird231102@mail.ru (E.V. Grachova). 1 Present address: Laboratoire de Chimie de Coordination, Institut de Chimie (UMR 7177 CNRS), Université de Strasbourg, 4 Rue Blaise Pascal, CS 90032, F-67081 Strasbourg Cedex, France. Contents lists available at SciVerse ScienceDirect Journal of Organometallic Chemistry journal homepage: www.elsevier.com/locate/jorganchem 0022-328X/$ e see front matter Ó 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.jorganchem.2012.03.003 Journal of Organometallic Chemistry 714 (2012) 22e31