Rhodium-catalyzed transfer hydrogenation with aminophosphines and analysis of electrical characteristics of rhodium(I) complex/n-Si heterojunctions Murat Aydemir a,b *, Yusuf Selim Ocak b,c , Khadichakhan Rafikova d , Nurzhamal Kystaubayeva d , Cezmi Kayan a , Alexey Zazybin d , Fatih Ok a , Akın Baysal a and Hamdi Temel b,e A series of novel neutral mononuclear rhodium(I) complexes of the P―NH ligands have been prepared starting from [Rh(cod) Cl] 2 complex. Structural elucidation of the complexes was carried out by elemental analysis, IR and multinuclear NMR spectro- scopic data. The complexes were applied to the transfer hydrogenation of acetophenone derivatives to 1-phenylethanol derivatives in the presence of 2-propanol as the hydrogen source. Catalytic studies showed that all complexes are also excellent catalyst precursors for transfer hydrogenation of aryl alkyl ketones in 0.1 M iso-PrOH solution. In particular, [Rh(cod)(PPh 2 NH―C 6 H 4 ―4-CH(CH 3 ) 2 )Cl] acts as an excellent catalyst, giving the corresponding alcohols in excellent con- version up to 99% (turnover frequency ≤ 588 h À1 ). Furthermore, rhodium(I) complexes have been used in the formation of organic–inorganic heterojunction by forming their thin films on n-Si and evaporating Au on the films. It has been seen that the structures have rectifying properties. Their electrical properties have been analyzed with the help of current– voltage measurements. Finally, it has been shown that the complexes can be used in the fabrication of temperature and light sensors. Copyright © 2014 John Wiley & Sons, Ltd. Keywords: aminophosphine; rhodium; transfer hydrogenation; heterojunction; temperature sensor Introduction Since the discovery that functional P-based ligands increase considerably the activity and/or selectivity of metal catalysts, the preparation of this type of ligand has been the subject of extensive investigations. [1–4] Small variations in these ligands can cause noteworthy changes in their coordination behavior and the structural features of the formed complexes. [5–9] Among these ligands, P―NH-containing ones have particular use in catalysis where it is necessary for part of the ligand to dissociate to allow an organic fragment to coordinate and undergo transformations. The presence of P―N ligands enables many differ- ent and important catalytic processes to occur including Heck [10,11] and Suzuki [12,13] reactions. A large number of complexes with aminophosphine ligands have also been evaluated in different catalytic reactions, including allylic alkylation, [14] amination, [15] Sonogashira, [16] hydroformylation, [17] hydrogenation [18] and poly- merization [19] reactions. Catalytic hydrogenation with the aid of a stable hydrogen donor is a useful alternative method for catalytic hydrogena- tion by molecular hydrogen. [20,21] In transfer hydrogenation, organic molecules such as primary and secondary alcohols [22] or formic acid and its salts [23] have been employed as the hydrogen source. In particular, transition-metal-catalyzed procedures for transfer hydrogenation of a wide variety of functional groups by different hydrogen donors are an interesting alternative to molecu- lar hydrogenation. [24] The hydrogenation of ketones, which is one of the most exciting and powerful methods of synthesizing alcohols, has been receiving increased attention as well and has led to extraordinary success. [25] Specifically, the catalytic transfer hydrogenation [26] of ketones is one of the most attractive methods for synthesizing secondary alcohols, which form an important class of intermediates for fine chemicals and pharmaceuticals. [27,28] There are several metal sources available that have to mediate the hydride transfer from the donor to the substrate. Even if main-group metals such as aluminum have historically been used in the transfer hydrogenation reactions, [29,30] today’s catalysts of * Correspondence to: Murat Aydemir, Department of Chemistry, Faculty of Science, University of Dicle, 21280 Diyarbakir, Turkey. E-mail: aydemir@dicle.edu.tr a Department of Chemistry, Faculty of Science, University of Dicle, 21280, Diyarbakir, Turkey b Science and Technology Application and Research Center, University of Dicle, 21280, Diyarbakir, Turkey c Department of Science, Faculty of Education, University of Dicle, 21280, Diyarbakir, Turkey d Department of Chemical Engineering, Kazakh–British Technical University, 050000, Almaty, Kazakhstan e Faculty of Pharmacy, University of Dicle, 21280, Diyarbakir, Turkey Appl. Organometal. Chem. 2014, 28, 396–404 Copyright © 2014 John Wiley & Sons, Ltd. Full Paper Received: 14 December 2013 Revised: 29 January 2014 Accepted: 18 February 2014 Published online in Wiley Online Library: 15 April 2014 (wileyonlinelibrary.com) DOI 10.1002/aoc.3140 396