Acetic acid solid state structure

X-Ray crystallographic analysis used alongside solution phase techniques such as NMR, is invaluable in the design of selective anion receptors as it can be used to define the solid-state structure of the anion-bound complex. Several X-ray structures of anion-bound complexes of [Ln.la]3+ have been defined recently (acetate, lactate, citrate, alanine, glycine, methionine, serine and threonine) [8,21,22], The complexes adopt a monocapped square antiprismatic structure with one base comprising of four N atoms of the macrocycle and the other base containing three O atoms of the pendent arms. The latter base is completed by a carboxylate O donor of the anion, which binds in a bidentate manner and simultaneously caps this base by O (acetate), OH (a-hydroxy acids) or NH2 (a-amino acids). The nature of the donor atom in the capping (or axial) position correlates well with the observed NMR shift in the solution phase. 

Acetic acid, cthylenediaminetetra-acid-base equilibria, 779 complexes composition, 783 coordination numbers, 783 solid state structure, 783 cyclic derivatives complexes, 785 heteroatom derivatives metal complexes, 786 homologs... 

Single crystal nmr spectra have been obtained for the resonance in K2Pt(CN)4Bro.3(H20)3, and the chemical shift tensor determined (565). The principal values (relative to the carboxyl carbon in acetic acid) have been reported as uu = 261 lOppm (parallel to the CN bond), <722 = — 48 10 ppm (perpendicular to the CN bond and Pt-Pt chain) and <733 = —10 5 ppm (parallel to the Pt-Pt chain). The primary effect on the chemical shift tensor of the cyanide bonding to the platinum and of the solid state structure is the nonzero asymmetry produced around the CN bond (565). 

Infra-red, microwave, and X-ray photoelectron spectroscopy Infra-red and ultra-violet spectroscopy has been widely used for investigating the structure of intermolecularly hydrogen-bonded complexes in the solid state (Novak, 1974) and in solution (Zundel, 1976, 1978 Clements et al., 1971a,b,c Pawlak et al., 1984). By analysing the infra-red spectra of equimolar liquid mixtures of amines with formic or acetic acid, the relative importance of structures [10] and [11] was estimated (Lindemann and Zundel, 1977). It was proposed that [10] and [11] make equal contributions to the observed structure of the complex when the p -value of the carboxylic acid is approximately two units lower than that of the protonated amine. 

Clathrate formation is very attractive for exploitation in solid-state chemistry. It allows one to modify in a simple way the environment of the guest molecule, to place this molecule in a crystalline phase with a structure different from its own (one structure may be chiral, and the other not), and even to achieve a stable crystalline structure at a temperature above the melting point of the pure guest. Some of the variety available for a single compound, acetic acid, is... 

Hydroxamic acids have been the subject of six papers 43 90 94 Earlier the operation of the a-effect in the reaction of p-nitrophcnyl acetate with benzohydroxamates in aqueous MeCN was discussed.43 The conformational behaviour of series of mono- (105) and di-hydroxamic acids (106) in MeOH, DMSO, and chloroform and in the solid state has been examined witii IR and NMR spectroscopy.90 X-ray crystal structure determinations of (105 X = Me, R = Me) and die monohydrate of glutarodihydroxamic acid (106 n = 3, R = H) together widi ab initio MO calculations for several hydrated and non-hydrated acids have been performed. The cis-Z conformation of the hydroxamate groups is preferentially stabilized by H-bonding witii water. 

Acetic acid treatment of the transition metal Ge(IV) hydride salt Kb/5-C5H5Mn(CO)2GeH3] yields a red product, b/5-C5H5Mn (CO)2]2Ge, which contains a linear Mn-Ge-Mn system in which the germanium atom occupies a special position with equal Ge-Mn distances of 2.204 A. Solution infrared spectra show four v(CO) stretching absorptions instead of the two expected from the cen-trosymmetric structure in the solid state, implying free rotation about the Ge-Mn bonds. Simple application of the rare-gas rule would favor a double-bonded formulation containing Ge(IV), but a molecular-orbital... 

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