The ability of multidimensional mass spectrometry (MS) approaches, interfacing different ionization methods with tandem mass spectrometry (MS2) fragmentation and ion mobility (IM) separation, to characterize synthetic polymers is demonstrated for poly(α-peptoid)s synthesized by N-heterocyclic carbene (NHC)-mediated zwitterionic ring-opening polymerization. Matrix-assisted laser desorption ionization (MALDI) causes elimination of the NHC initiator, if performed in the presence of cationizing salts. Electrospray ionization (ESI) is softer, allowing for the detection of the intact sample. It also shows that in proper solvents self-assembly of the poly(α-peptoid) occurs to form supramacromolecules; since these noncovalent self-assemblies overlap with the main product, separation by IM MS is essential for their conclusive identification. MS2 confirms the connectivity of the poly(α-peptoid)s, whereas MS2 combined with IM separation renders valuable insight into the binding interactions in the supramolecular ass...
Xiaopeng Li; Li Guo; Madalis Casiano-Maldonado; Donghui Zhang; Chrys Wesdemiotis
The two enantiomers of 2-(2-hydroxybiphenyl-4-yl)propanoic acid ((S)- and (R)-BPOH) have been selected as probes for human serum albumin (HSA). Photophysical characterization in the absence of protein led to emission maxima, singlet energies, quantum yields, and fluorescence lifetime values ... more
The photodissociation of H2O in its B band is a prototype for nonadiabatic reaction dynamics. In addition to dissociation via the adiabatic pathway to the OH(Ã2Σ+) + H fragments, it also produces the OH(X̃2Π) + H fragments through two nonadiabatic pathways: the B̃ → X̃ transition via two co ... more
Due to the widespread occurrence in the environment and potential risk toward organisms of fluoroquinolones (FQs), it is of importance to develop high efficient methods for assessing their occurrence and environmental risk. A monoclonal antibody (Mab) with broad cross-reactivity to FQs was ... more
Rohm and Haas Powder Coatings is delighted to announce that its Reading, Pennsylvania, facility is the first site in the world to receive the RCMS® Site Certification awarded by the American Chemical Council (ACC).
When Raj Gupta, Chairman and CEO of Rohm and Haas Company, became Chairman ... more