Pike, Sebastian D. and Krämer, Tobias and Rees, Nichollas H. and Macgregor, Stuart A. and Weller, Andrew S. (2015) Stoichiometric and Catalytic Solid−Gas Reactivity of Rhodium Bis-phosphine Complexes. Organometallics, 34 (8). pp. 1487-1497. ISSN 0276-7333

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Abstract

The complexes [Rh(iBu2PCH2CH2PiBu2)L2][BArF4] [L2 = C4H6, (C2H4)2, (CO)2, (NH3)2; ArF = 3,5-C6H3(CF3)2] have been synthesized by solid−gas reactivity via ligand exchange reactions with, in some cases, crystallinity retained through single-crystal to single-crystal transformations. The solid-state structures of these complexes have been determined, but in only one case (L2 = (NH3)2) is the cation ordered sufficiently to enable its structural metrics to be determined by single crystal X-ray diffraction. The onward solid-state reactivity of some of these complexes has been probed. The bis-ammonia complex [Rh(iBu2PCH2CH2PiBu2)(NH3)2][BArF4] undergoes H/D exchange at bound NH3 when exposed to D2. The bis-ethene complex [Rh(iBu2PCH2CH2PiBu2)(C2H4)2][BArF4] undergoes a slow dehydrogenative coupling reaction to produce a material containing a 1:1 mixture of the butadiene complex and a postulated mono-ethene complex. The mechanisms of these processes have been probed by DFT calculations on the isolated Rh cations. All the solid materials were tested as heterogeneous catalysts for the hydrogenation of ethene. Complexes with weakly bound ligands (e.g., L2 = (C2H4)2) are more active catalysts than those with stronger bound ligands (e.g., L = (CO)2). Surface-passivated crystals, formed through partial reaction with CO, allow for active sites to be probed, either on the surface or the interior of the single crystal.

Item Type:	Article
Keywords:	Stoichiometric; Catalytic Solid−Gas Reactivity; Rhodium Bis-phosphine Complexes;
Academic Unit:	Faculty of Science and Engineering > Computer Science Faculty of Science and Engineering > Research Institutes > Hamilton Institute
Item ID:	15500
Identification Number:	https://doi.org/10.1021/om5013133
Depositing User:	Tobias Kraemer
Date Deposited:	15 Feb 2022 12:35
Journal or Publication Title:	Organometallics
Publisher:	American Chemical Society
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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