TY - JOUR

T1 - Proton solvates, H+·nH2O·mL, formed by diphosphine dioxides with chlorinated cobalt(III) dicarbollide acid

AU - Stoyanov, Evgenii S.

AU - Smirnov, Igor V.

PY - 2005/4/25

Y1 - 2005/4/25

N2 - Interaction of hydrated proton, H5O2 +·(H2O)4, in dichloroethane solutions with diphosphine dioxides (L) having methyl (Ph4Me), ethyl (Ph 4Et) and polyoxyethylene chains (Ph4PEG) linking two diphenyl phosphine oxide groups has been investigated. A bulky counter ion: chlorinated cobalt(III) bis(dicarbollide), [Co(C2B9H 8Cl3)2]-, minimizes perturbation of the cation. At low concentrations, Ph4Et and Ph4PEG form anhydrous 1:1 complexes with (P)O-H+-O(P) fragment having very strong symmetrical H-bonds. At these conditions Ph4Me form another compound, H5O2+·L(H2O) 2, due to lower PO basicity and optimal geometry of the chelate cycle. At higher concentrations, Ph4Me and Ph4Et form isostructural complexes H5O2+·L 2, whereas Ph4PEG forms only a 1:1 complex with proton dihydrate, H3O+·H2O. In excess of free Ph4Me and Ph4Et a water molecule is introduced to the first coordination sphere of H5O2+ and the average molar ratio L/H5O2+ of the complexes exceeds 2. The composition of these complexes as a function of L and its concentration is discussed.

AB - Interaction of hydrated proton, H5O2 +·(H2O)4, in dichloroethane solutions with diphosphine dioxides (L) having methyl (Ph4Me), ethyl (Ph 4Et) and polyoxyethylene chains (Ph4PEG) linking two diphenyl phosphine oxide groups has been investigated. A bulky counter ion: chlorinated cobalt(III) bis(dicarbollide), [Co(C2B9H 8Cl3)2]-, minimizes perturbation of the cation. At low concentrations, Ph4Et and Ph4PEG form anhydrous 1:1 complexes with (P)O-H+-O(P) fragment having very strong symmetrical H-bonds. At these conditions Ph4Me form another compound, H5O2+·L(H2O) 2, due to lower PO basicity and optimal geometry of the chelate cycle. At higher concentrations, Ph4Me and Ph4Et form isostructural complexes H5O2+·L 2, whereas Ph4PEG forms only a 1:1 complex with proton dihydrate, H3O+·H2O. In excess of free Ph4Me and Ph4Et a water molecule is introduced to the first coordination sphere of H5O2+ and the average molar ratio L/H5O2+ of the complexes exceeds 2. The composition of these complexes as a function of L and its concentration is discussed.

KW - Diphosphine dioxides

KW - IR spectroscopy

KW - Proton hydrates and solvates

KW - Strong H-bonds

UR - http://www.scopus.com/inward/record.url?scp=16344382751&partnerID=8YFLogxK

U2 - 10.1016/j.molstruc.2004.12.037

DO - 10.1016/j.molstruc.2004.12.037

M3 - Article

AN - SCOPUS:16344382751

VL - 740

SP - 9

EP - 16

JO - Journal of Molecular Structure

JF - Journal of Molecular Structure

SN - 0022-2860

IS - 1-3

ER -