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Ab Initio And 1H Nmr Study Of The Zn(Ii) Complexes Of A Nido- And A Closo-Carboranylporphyrin, Petia Bobadova-Parvanova, Yuko Oku, Anura Wickramasinghe, Randall W. Hall, Graca H. Vicente Jun 2004

Ab Initio And 1H Nmr Study Of The Zn(Ii) Complexes Of A Nido- And A Closo-Carboranylporphyrin, Petia Bobadova-Parvanova, Yuko Oku, Anura Wickramasinghe, Randall W. Hall, Graca H. Vicente

Randall W. Hall

n ab initio study of a promising nido-carboranylporphyrin for the boron neutron capture therapy of tumors, and of its closo precursor is reported. Base-induced deboronation of neutral ZnDCP, believed to exist as a mixture of 3 stereoisomers, produces the tetraanionic ZnDCP4- as a complex mixture of isomers. 1H NMR data and ab initio calculations support these findings. The position of the axial pyridine ligand in ZnDCP4- and the orientation of the endo hydrogen atoms on the open faces of the nido-carborane cages significantly influence the total energy of the ZnDCP4- structures. It is suggested that the "cocktail" of isomers possibly …


Tools And Strategies For Processing Diffusion-Ordered 2d Nmr Spectroscopy (Dosy) Of A Broad, Featureless Resonance: An Application To Methylaluminoxane (Mao), Jan Lasse Eilertsen, Randall W. Hall, Larry S. Simeral, Leslie G. Butler Feb 2004

Tools And Strategies For Processing Diffusion-Ordered 2d Nmr Spectroscopy (Dosy) Of A Broad, Featureless Resonance: An Application To Methylaluminoxane (Mao), Jan Lasse Eilertsen, Randall W. Hall, Larry S. Simeral, Leslie G. Butler

Randall W. Hall

DOSY has been extremely successful in many studies of molecular weight distributions, especially when the components are separable along the chemical shift axis. However, an unresolved NMR resonance yields the familiar problem of overlapping exponential decays. In a study of methylaluminoxane (MAO), a set of data processing and simulation tools were developed: read Bruker data files (Matlab); preliminary non-linear least-squares fit with f-test (Matlab); movie generation of the fits (Matlab); conversion of diffusion coefficients to molecular masses through molecular volumes (Gaussian-98); and simulation of DOSY data sets for various molecular mass distributions (Mathematica). These tools are presented here and briefly …