172220-60-9Relevant academic research and scientific papers
Cyanide Ligand Basicities in Cp′M(L)2CN Complexes (M = Ru, Fe). Correlation between Heats of Protonation and vCN
Nataro, Chip,Chen, Jiabi,Angelici, Robert J.
, p. 1868 - 1875 (2008/10/08)
Basicities of the cyanide ligands in a series of Cp′M(L)2CN complexes were investigated by measuring their heats of protonation (-δHCNH) by CF3SO3H in 1.2-dichloroethane solution at 25.0 °C to give Cp′M(L)2(CNH)+CF3SO3 -, in which the N-H+ group is probably hydrogen-bonded to the CF3SO3- anion. Basicities (-δHCNH) of the CpRu(PR3)2CN complexes increase from 20.5 (PPh3) to 22.4 (PMe3) kcal/mol with increasing donor abilities of the phosphine ligands. Basicities of all the Cp′Ru(PR3)2CN complexes, where Cp′ = Cp or Cp*, are linearly correlated with their vCN values; the nonphosphine complexes. CpRu(l.10-phen)CN and CpRu(COD)CN, do not follow the same correlation. For a large number of Cp′M(L)2CN complexes (M = Ru, Fe, L2 = mono- and bidentate phosphines, CO, 1,10-phen, and COD), their vCN values parallel vCN values of their protonated Cp′M(L)2(CNH)+ analogues. Also, 31P NMR chemical shifts of the unprotonated Cp′M(PR3)2-CN and protonated CpM(PR3)2(CNH)+ complexes are linearly related. Despite the high basicity of Ru in Cp*Ru-(PMe3)2Cl (30.2 kcal/mol), the CN- in Cp*Ru(PMe3)2CN (25.0 kcal/mol) is the site of protonation: factors that determine whether protonation occurs at the Ru or the CN- are discussed.
Enthalpies of reaction of Cp′Ru(COD)Cl (Cp′ = C5H5, C5Me5; COD = cyclooctadiene) with P(p-XC6H4)3 (X = Cl, F, H, CH3, CF3, OCH3) ligands: Ligand steric vs electronic contributions to the enthalpy of reaction
Serron, Scafford A.,Luo, Lubin,Li, Chunbang,Cucullu, Michèle E.,Stevens, Edwin D.,Nolan, Steven P.
, p. 5290 - 5297 (2008/10/09)
The enthalpies of reaction of Cp′Ru(COD)Cl (1; Cp′ = η5-C5H5, η5-C5Me5; COD = cyclooctadiene) with a series of para-substituted monodentate tertiary phosphine ligands, leading to the formation of Cp′Ru(PR3)2Cl, have been measured by anaerobic solution calorimetry in THF at 30.0°C. These reactions are rapid and quantitative. Structural studies have been carried out on three complexes in this series. The relative importance of phosphine steric vs electronic ligand parameters is more closely examined in terms of the presented quantitative thermochemical and structural information. Comparisons with enthalpy data in this and related organometallic systems are also presented.
