Synthesis, reactivity and crystal structures of various solvates of fac-tris(trimethylphosphine)trichloroiridium Joseph S. Merola ⇑ , Marion A. Franks, Joy F. Frazier Department of Chemistry, Virginia Tech, Blacksburg, VA 24061, USA article info Article history: Received 16 August 2012 Accepted 13 February 2013 Available online 20 February 2013 Keywords: Phosphine iridium complexes Iridium chloride complexes Iridium complex isomers Crystal packing forces Iridium phosphine chlorides abstract The synthesis of fac-tris(trimethylphosphine)iridiumtrichloride is reported and the crystal structure of five different solvates of this compound are analyzed. Compared with the idealized structure calculated with DFT methods, bond angles and distances differ considerably for all of the solvates examined. The utility of fac-tris(trimethylphosphine)iridiumtrichloride for the synthesis of organometallic compounds of iridium(III) is also demonstrated. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Metal phosphine complexes have been widely studied and have had an enormous impact on the study of homogeneous catalysis [1]. Triphenylphosphine in combination with rhodium has been a huge commercial success in the low pressure hydroformylation reaction [2–5]. Specially designed phosphines have been used in asymmetric catalysis also seeing commercial success for the pro- duction of L-DOPA [6–8]. Trialkylphosphines that are more elec- tron donating have been used to synthesize very electron-rich metal complexes that have been useful for carrying out oxidative addition reactions with substrates, such as C–H bonds, that do not normally react readily. Specifically, the smallest trialkylphos- phine, trimethylphosphine, has been used to synthesize complexes that are capable of some very intriguing reaction chemistry and stabilizing compounds that are proposed only as intermediates in other systems [9–18]. A complete review of phosphine metal com- plexes or even trimethylphosphine metal complexes is not possible here, but there are some reviews and texts that do provide a good overall introduction [3,19–21]. We have found the specific combination of trimethylphosphine and iridium (or rhodium) has been a particularly powerful one, especially for studying oxidative addition reactions of B–H, C–H, N–H and O–H bonds. We have previously reported on the synthesis and reaction chemistry of [Ir(COD)(PMe 3 ) 3 ]Cl, 1, which is a very convenient, stable, electron-rich iridium complex [22–29]. In a recent paper, we described the protonation chemistry of 1 [30]. In this paper, we report on some of the further reaction chemistry of protonated complex 1 that involves the synthesis, structures and synthetic utility of fac-tris(trimethylphosphine)iridium trichloride. 2. Experimental 2.1. General procedures Toluene, ether, and pentane were purchased from Fisher Scientific. Toluene was distilled from potassium benzophenone; dichlorometh- ane was distilled from P 2 O 5 ; ether and pentane were distilled over Na/K alloy. Water was deionized and distilled. Deuterated solvents were purchased from Cambridge Isotope Laboratories and dried over molecular sieves. Hydroiridic acid was purchased from PGN Chemi- cals and was used as received. [Ir(COD)Cl] 2 was prepared using a method analogous to the literature procedure [31]. [Ir(COD)(PMe 3 ) 3 ] Cl and [Ir(COD)(PMe 3 ) 3 ]BF 4 were prepared as described previously [32]. Also, mer-IrCl 3 (PMe 3 ) 3 was prepared as described previously for other trialkylphosphine complexes [33]. The 1 H and 31 P NMR spectra were recorded on a Bruker WP200 SY spectrometer operating at 200.132 MHz for protons, 81.015 MHZ for phosphorus, 67.925 MHz for carbon, or a Bruker WP360 SY spectrom- eter operating at 360.134 MHz for protons, 145.785 MHz for phos- phorus, and 90.556 MHz for carbon. Elemental analyses were performed by Atlantic Microlabs Inc., Norcross, Georgia. 2.2. Syntheses 2.2.1. Synthesis of fac-(Me 3 P) 3 IrCl 3 H 2 O, 3a Compound 2, (50 mg, 0.074 mmol) was placed into a 2 dram vial and was dissolved in water (2.5 mL). The vial was allowed to 0277-5387/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.poly.2013.02.021 ⇑ Corresponding author. Tel.: +1 540 231 4510; fax: +1 540 231 3255. E-mail address: jmerola@vt.edu (J.S. Merola). Polyhedron 54 (2013) 67–73 Contents lists available at SciVerse ScienceDirect Polyhedron journal homepage: www.elsevier.com/locate/poly