Metal-Dependant Structural Families of Aminomethylphosphonic Acid Assemblies Differentiated by Ion Mobility Mass Spectrometry and Density Functional Theory

Abstract

Herein the morphology of aminomethylphosphonic acid (AMPA)-metal aggregates are analysed by ion mobility-mass spectrometry, DFT and IRMPD spectroscopy. Matching experimental collision cross section to the DFT predicted minima allowed unambiguous assignment of [M(AMPA)(AMPA-H)]⁺ where M = Mg²⁺, Ca²⁺, and Mn²⁺. Two distinct structural families of [M(AMPA)(AMPA-H)]⁺ M = Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Cu²⁺, and Zn²⁺. were differentiated by ion mobility – mass spectrometry. Groupings of experimental collision cross sections were observed for a square pyramidal geometry, (M = Ca²⁺, Sr²⁺, Ba²⁺) versus a seesaw geometry (M = Mg²⁺, Mn²⁺, Cu²⁺, and Zn²⁺), paving the way for distinction of aggregates at the earliest stages of assembly.