Noncovalent interactions and internal dynamics in dimethoxymethane-water.
The millimeter-wave absorption and Fourier transform microwave spectra of five isotopologues of the 1:1 adduct of dimethoxymethane-water have been measured in supersonic expansions. Each rotational transition appears as a quintuplet, due to the internal rotation of the two methyl groups, which are nonequivalent in the adduct. The water moiety, linked asymmetrically to dimethoxymethane, behaves as a proton donor to one of its oxygen atoms and interferes with the internal rotation of the farther methyl group through a C...HO interaction. From the analysis of the observed splittings, the V(3) barriers to the internal rotation of the two methyl groups have been determined to be 6.83(8) and 6.19(8) kJ mol(-1). The hydrogen bond structural parameters have been determined, the O...HO and C...HO distances being 1.93(1) and 2.78(4) A, respectively.
Favero
Laura B
LB
Istituto per lo Studio dei Materiali Nanostrutturati ISMN, Sezione di Bologna, CNR, Via Gobetti 101, 40129 Bologna, Italy.
Giuliano
Barbara M
BM
Melandri
Sonia
S
Maris
Assimo
A
Caminati
Walther
W