TY - JOUR

T1 - Solid-state and solution-state self-association of dimethylarsinic acid: IR, NMR and theoretical study

AU - Mulloyarova, Valeriia V.

AU - Puzyk, Aleksandra M.

AU - Efimova, Alexandra A.

AU - Antonov, Alexander S.

AU - Evarestov, Robert A.

AU - Aliyarova, Irina S.

AU - Asfin, Ruslan E.

AU - Tolstoy, Peter M.

N1 - Funding Information: Authors acknowledge the financial support of the Russian Science Foundation (Project RSF 18?13?00050). Analytical measurements and calculations were performed using the facilities of St. Petersburg State University Research Park: optical spectra were obtained at the Center for Geo-Environmental Research and Modeling (GEOMODEL), NMR spectra were recorded at the Center for Magnetic Resonance, X-Ray studies were performed at the Center for X-ray Diffraction Studies, quantum-chemical calculations were conducted at the Computing Center of St. Petersburg State University (http://cc.spbu.ru). Publisher Copyright: © 2021 Elsevier B.V. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/6/15

Y1 - 2021/6/15

N2 - The structure of dimethylarsinic acid (Me2AsOOH, DMA) in crystal and in solution in aprotic medium was studied by X-ray, spectroscopic (IR, NMR and Raman) and quantum chemical calculation (DFT) methods. Two polymorphs of DMA – hydrogen-bonded cyclic dimers or infinite chains – were obtained by growing crystals from protic and aprotic solvents. By comparison of the experimental data with the results of quantum-chemical calculations performed with periodic boundary conditions we propose ways how to distinguish two polymorphs using IR marker bands. The self-association of DMA in polar aprotic solution was studied by low-temperature NMR (T = 100 K, solvent CDF3/CDF2Cl mixture). By using H/D isotope effects on 1H NMR chemical shifts (appearing after a partial deuteration of DMA in the mobile proton sites) we were able to prove that in solution DMA forms cyclic dimers with two equivalent strong hydrogen bonds (in contrast, for example, to Me2POOH acid, which forms predominantly cyclic trimers). Based on the available IR spectra, the type of complexation does not change when the aprotic solvent is varied.

AB - The structure of dimethylarsinic acid (Me2AsOOH, DMA) in crystal and in solution in aprotic medium was studied by X-ray, spectroscopic (IR, NMR and Raman) and quantum chemical calculation (DFT) methods. Two polymorphs of DMA – hydrogen-bonded cyclic dimers or infinite chains – were obtained by growing crystals from protic and aprotic solvents. By comparison of the experimental data with the results of quantum-chemical calculations performed with periodic boundary conditions we propose ways how to distinguish two polymorphs using IR marker bands. The self-association of DMA in polar aprotic solution was studied by low-temperature NMR (T = 100 K, solvent CDF3/CDF2Cl mixture). By using H/D isotope effects on 1H NMR chemical shifts (appearing after a partial deuteration of DMA in the mobile proton sites) we were able to prove that in solution DMA forms cyclic dimers with two equivalent strong hydrogen bonds (in contrast, for example, to Me2POOH acid, which forms predominantly cyclic trimers). Based on the available IR spectra, the type of complexation does not change when the aprotic solvent is varied.

KW - Cacodylic acid

KW - Crystal structure

KW - Hydrogen bonding

KW - Polymorph

KW - Structure of self-associate

KW - HYDROGEN-BOND

KW - CRYSTAL-STRUCTURE

KW - COMPLEXES

KW - DIMERIZATION

KW - BAND

KW - DIMERS

KW - SOLVENT

KW - PHOSPHINIC ACIDS

KW - GAS-PHASE

KW - SPECTRA

UR - http://www.scopus.com/inward/record.url?scp=85102053285&partnerID=8YFLogxK

U2 - 10.1016/j.molstruc.2021.130176

DO - 10.1016/j.molstruc.2021.130176

M3 - Article

AN - SCOPUS:85102053285

VL - 1234

JO - Journal of Molecular Structure

JF - Journal of Molecular Structure

SN - 0022-2860

M1 - 130176

ER -