Electrospray-friendly ligands for the mass spectral analysis of transition-metal complexes
type: CreativeWork
description: The key aim of this project was to develop the concept of electrospray-friendly ligands as a new ionisation method for the analysis of neutral metal complexes by electrospray mass spectrometry (ESMS). This involved introducing active functional groups into traditional ligands which do not otherwise undergo chemical ionisation under ESMS conditions. Electrospray-friendly ligands (as illustrated above for PPh₃ derivatives) were incorporated into a series of metal carbonyl complexes of Mo, Fe and Ru, metal halide complexes of Pd, Pt and Au, and a number of zero-valent complexes of Pt and Pd. All carbonyl complexes with ES-friendly phosphine, arsine and stibine ligands ionised by protonation, yielding strong [M + H]⁺ ions as the only signals in the spectrum. The metal halide complexes followed the known halide-loss mechanism. Pt(0) and Pd(0) complexes did not require functionalised ligands, as their PPh₃ derivatives already gave [M +H]⁺ ions. Mo and W carbonyl complexes of the two ‘naturally’ electrospray friendly ligands tpa (tpa = 1,3,5-triaza-7-phosphaadamantane) and tcep [tcep = tris(2-cyanoethyl)phosphine] could also be studied readily by ESMS. While all tpa complexes gave [M + H]⁺ ions, complexes of tcep preferred ionisation by NH₄⁺. The ionisation efficiencies of selected ligands and complexes are discussed. Thiolate complexes of Ni, Pd, Pt, Au and Hg were prepared using the ligands SC₆H₄OMe-p (S*) and p-SC₅H₄N (S•), but only the S•-complexes reliably underwent the protonation-type mechanism. The Cd-thiolate complexes [Cd₄(SPh)₁₀]²⁻, [S₄Cd₁₀(SPh)₁₆]⁴⁻ and [S₄Cd₁₀(SPh)₂₈]²⁻ underwent rapid ligand exchange with S*, but yielded insoluble products with S•. The complexes [Pt₂(μ-S)₂(L)₂] (L = PPh₃, P*, P**, P***. P•. As***¹) were prepared, and by means of ESMS, aspects of ligand exchange as well as reactivity towards other metal centres were investigated. Isonitrile derivatives of [Fe₃(CO)₁₂] and [Ru₃CO)₁₂] were prepared by ligand exchange with CNPh, CNC₆H₄OMe-p (CNPh*…
abstract: The key aim of this project was to develop the concept of electrospray-friendly ligands as a new ionisation method for the analysis of neutral metal complexes by electrospray mass spectrometry (ESMS). This involved introducing active functional groups into traditional ligands which do not otherwise undergo chemical ionisation under ESMS conditions. Electrospray-friendly ligands (as illustrated above for PPh₃ derivatives) were incorporated into a series of metal carbonyl complexes of Mo, Fe and Ru, metal halide complexes of Pd, Pt and Au, and a number of zero-valent complexes of Pt and Pd. All carbonyl complexes with ES-friendly phosphine, arsine and stibine ligands ionised by protonation, yielding strong [M + H]⁺ ions as the only signals in the spectrum. The metal halide complexes followed the known halide-loss mechanism. Pt(0) and Pd(0) complexes did not require functionalised ligands, as their PPh₃ derivatives already gave [M +H]⁺ ions. Mo and W carbonyl complexes of the two ‘naturally’ electrospray friendly ligands tpa (tpa = 1,3,5-triaza-7-phosphaadamantane) and tcep [tcep = tris(2-cyanoethyl)phosphine] could also be studied readily by ESMS. While all tpa complexes gave [M + H]⁺ ions, complexes of tcep preferred ionisation by NH₄⁺. The ionisation efficiencies of selected ligands and complexes are discussed. Thiolate complexes of Ni, Pd, Pt, Au and Hg were prepared using the ligands SC₆H₄OMe-p (S*) and p-SC₅H₄N (S•), but only the S•-complexes reliably underwent the protonation-type mechanism. The Cd-thiolate complexes [Cd₄(SPh)₁₀]²⁻, [S₄Cd₁₀(SPh)₁₆]⁴⁻ and [S₄Cd₁₀(SPh)₂₈]²⁻ underwent rapid ligand exchange with S*, but yielded insoluble products with S•. The complexes [Pt₂(μ-S)₂(L)₂] (L = PPh₃, P*, P**, P***. P•. As***¹) were prepared, and by means of ESMS, aspects of ligand exchange as well as reactivity towards other metal centres were investigated. Isonitrile derivatives of [Fe₃(CO)₁₂] and [Ru₃CO)₁₂] were prepared by ligand exchange with CNPh, CNC₆H₄OMe-p (CNPh*…
author: Decker, Corry
license: https://researchcommons.waikato.ac.nz/bitstreams/b6a66465-88c3-4152-9e3e-3159b610fb03/download
date published: 2002
date modified: 2026-07-24T05:57:41Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato