1404466-80-3Relevant academic research and scientific papers
Lanthanide complexes of the klaeui metalloligand, CpCo(P=O(OR) 2)3: An examination of ligand exchange kinetics between isotopomers by electrospray mass spectrometry
Allen, Kevin J. H.,Nicholls-Allison, Emma C.,Johnson, Kevin R. D.,Nirwan, Rajinder S.,Berg, David J.,Wester, Dennis,Twamley, Brendan
, p. 12436 - 12443 (2012)
A series of lanthanide complexes, {[CpCo(P=O(OR)2) 3]2Ln(H2O)x}+Cl - (Ln = Nd, 3; Eu, 4; Tb, 5; Yb, 6; R = Et, a; R = Ph, b) bearing two cobalt metalloligands were prepared. Electrospray mass spectrometry and thermogravimetric analysis suggest that the cations are either solvent-free or contain very weakly bound water molecules. The related complex {[CpCo(P=O(OPh)2)3]2Yb}+ [CoCl 3(THF)]-, 7, was crystallographically characterized, and the cation in this case was confirmed to be 6-coordinate and solvent-free. Ligand exchange rates between the d0- and d60-isotopomers of 3a-6a and 5b were determined in acetonitrile by electrospray mass spectrometry. The ligand exchange rate was found to increase by almost 4 orders of magnitude from the smallest (Yb, 6a, k = 0.3 M-1 s-1) to largest ion (Nd, 3a, >2500 M-1 s-1) in acetonitrile. Additionally, the ligand exchange rate increased rapidly for 5a (Tb) with increasing water concentration from 30 M-1 s-1 in pure acetonitrile to 268 M-1 s-1 in 50:50 (v/v) acetonitrile/water. Changing the phosphite substituent had no significant impact on the rate of ligand exchange for 5b (R = Ph) relative to 5a (R = Et).
