22654-78-0Relevant academic research and scientific papers
Promoting effect of ionic liquids on ligand substitution reactions
Sliger, Michael D.,P'Pool, Steven J.,Traylor, Rachel K.,McNeill III, James,Young, Sidney H.,Hoffman, Norris W.,Klingshirn, Marc A.,Rogers, Robin D.,Shaughnessy, Kevin H.
, p. 3540 - 3545 (2008/10/09)
Ionic liquid solvents N-hexylpyridinium bistrifylimide ([C 6pyr][Tf2N]] and 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) promoted the displacement of anionic ligands by pyridine derivatives in trans-(Ph 3P)2Rh(CO)NO3 to a much greater extent than did dichloromethane. Thus, addition of a slight excess of 2-fluoropyridine to trans-(Ph3P)2Rh(CO)NO3 in [C 4mim][PF6] gave a 29:71 product mixture of trans-(Ph 3P)2Rh(CO)NO3:[trans-(Ph3P) 2Rh(CO)(2-fluoropyridine)][NO3], while the ratio was 91:9 in dichloromethane.
Structural and Spectroscopic Studies of Rhodium-(I) and -(III) Nitrato Complexes
Heaton, Brian T.,Iggo, Jonathan A.,Jacob, Chacko,Blanchard, Helen,Hursthouse, Michael B.,et al.
, p. 2533 - 2538 (2007/10/02)
Refluxing Rh(NO3)3*2H2O with an excess of PPh3 in MeOH or EtOH for over 48 h gives trans- 1 whereas the same reaction at room temperature gives predominantly 2.X-Ray structure determinations of 1 and 2 show the nitrate groups to be monodentate in each case although disorder of the CO and NO3 groups in 1 precludes accurate determination of bond lengths and angles.There is no reaction of trans- (X = Cl, F or ONO2) with H2 at room temperature and 1 atm pressure, whereas there is an intermediate reaction of under the same conditions to give 3, which has been characterised by multinuclear NMR spectroscopy.Compound 3 loses PPh3 to give 6a which has been characterised similarly and by X-ray crystallography; although the metal-bound hydrogens were not located the structure is clearly based on an octahedral geometry with trans phosphines and a bidentate nitrate.
Relative affinities of carbonylbis(triphenylphosphine)rhodium(I) and related cations for anionic ligands in CH2Cl2
Araghizadeh, Farshid,Branan, Daniel M.,Hoffman, Norris W.,Jones, John H.,McElroy, E. Andrew,Miller, Nathan C.,Ramage, David L.,Salazar, Anna Battaglia,Young, Sidney H.
, p. 3752 - 3755 (2008/10/08)
Infrared spectroscopy has been used to determine the relative anion affinities in CH2Cl2 of Rh(PPh3)2(CO)+ and Rh(AsPh3)2(CO)+ via measurement of equilibrium constants for the metatheses RhL2(CO)Y + PPN+Z- = RhL2(CO)Z + PPN+Y-. Observed for L = PPh3 was the anion affinity trend NCO- ? O2CMe- ～ O2CPh- ? F- ～ NCS- > Cl- > Br- > I- ? ONO2- ～ O2CCF3- ? OTf- ～ OClO3-. A smaller series for L = AsPh3 displayed a similar trend, but with positions of NCS- and Cl- reversed. For most anion pairs studied, the equilibrium lies so far to the left or right that only limits could be calculated, given the inherent experimental limitations. For L = PPh3, the equilibrium constant for replacement of the least preferred anion by the most can be inferred as >1019. Rh(PCy3)2(CO)Cl and Rh(PCy3)2(CO)Z (Z = NCS, NCSe, O2CMe; but not F, O2CPh, and NCO) interact strongly in solution and thus limit study of that series.
