Formic acid solid state structure

See Table III.) Bismuth formate Bi(OOCH)3 is prepared by reacting bismuth oxide with a 40% formic acid solution under reflux conditions (50, 64). The solid-state structure shows three different Bi-0 distance ranges [avg. 2.38, 2.52, and 2.77 A] and all oxygen atoms interacting with bismuth, which occupies a six-coordinate, distorted octahedral environment. The octahedra are linked via the carbon centers re-... 

Fig. 29 Solid-state structure of the cyclic four-component assembly of 2(carbamazapine)-2(formic acid).

A tentative mechanism has been proposed for the Pd(OAc)2-catalyzed hydrocarboxylation of alkynes with formic acid (Scheme 2). Beginning with step A, the solid-state structure of Pd(OA)2 breaks down and the Pd(ll) complex is reduced to Pd(0) under CO. The catalytic species [Pd(CO) ,(PR3)] c is then formed in the presence of phosphine... 

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. 

Quasi-solid state dye-sensitized solar cells (DSCs) have been constructed using a new polymeric ionic fluid as the electrolyte.119 The electrolyte was synthesized by the sol-gel route using MTMSPI+I as the precursor that was made by derivatizing methylimidazolium with triethyoxysilane. Condensation of this material in the presence of formic acid and in the absence of water led to Si-O-Si-O-type polymerization and formation of a polysilsesquioxane-type structure. When this material was mixed with iodine, it served as a redox electrolyte for DSCs. The DSCs made this way are robust and easy to assemble but their efficiency of 3.1% is relatively low. However, possible improvement lies in modification of the organic groups attached to the polysilsesquioxane backbone. 

It was found meanwhile that nearly every slim unbranched polymer chain, such as poly(trimethylene oxide) [224], poly(l,3-dioxolane) [225], poly(tetramethylene oxide) [226], polyethylene imine) [227], poly(3-hydroxy propionate), poly (4-hydroxybutyrate) and poly(6-hydroxyhexanoate) [228,229], poly(butylene succinate) [229], polyadipates [230], nylon-6 [231], and even oligomers of polyethylene [232], form a-CD ICs with channel structures. In all of these cases, inclusion is a heterogeneous process, since the guest polymer and its CD complex are almost insoluble in water. Therefore, extensive sonication had to be applied to accelerate the diffusion process. The polymer was also dissolved in an organic solvent, e.g., nylon-6 in formic acid, and this solution was added to the solution of a-CD [231], Alternatively, a monomer, such as 11-aminoundecanoic acid, was included in a-CD and polymerized to nylon-11 by solid state polycondensation within the channels of the IC. Thus, the IC of nylon-11 was formed under conservation of the crystal packing [233-235],... 

Fig. 10.5 In the vapour state, formic acid exists as both (a) a monomer and (b) a dimer, the structures of which have been determined by electron diffraction, (c) In the solid state, a more complex assembly is formed as revealed in a neutron diffraction study of deuterated formic acid, DCO2D the figure shows part of the packing diagram for the unit cell. [A. Albinati et al. (1978) Acta Crystallogr., Sect. B, vol. 34, p. 2188.] Distances are in pm. Colour code C, grey O, red H, white D, yellow.

Many studies carried out with bimetallic materials show that Pt-Ru is today one of the best options to oxidize methanol. Thus, a simple way to prepare active Pt-Ru catalysts involves the deposition of metallic nanoparticles from a suspention onto the carbon microparticles by the method known as formic acid method [24]. Considering that the crystal structures of Pt and Ru are different, Pt being fee and Ru hep, the final crystal structure of the alloy depends on the composition. For Ru atomic fractions up to 0.6-0.7, the two metals form solid solutions in which Ru atoms replace Pt lattice points in the fee structure. The opposite situation, Pt atoms replacing Ru atoms in the hep structure is found for Ru atomic fractions higher than about 0.7. However, the crystal structure seems to depend also on the physical state of the material. When nanoparticles are prepared by reduction of ionic metal species, there is at least one report [25] claiming that the fee stmeture prevails up to 80 at.%Ru. On the other hand in sputtered films the hep structure is predominant even at low Ru fractions [26]. 

Yao, J., Ohgo, K., Sugino, R., Kishore, R., Asakura, T., 2004. Structural analysis of Bombyx mori silk fibroin peptides with formic acid treatment using high-resolution solid-state C NMR spectroscopy. Biomacromolecules 5 (5), 1763—1769. 

In research involving cocrystals of the model pharmaceutical compound caffeine (29a) was prepared via solid-state grinding (a Retsch MM200 mixer mill was used) and solution crystallization, it was demonstrated that these two methods of preparation are not always equivalent with respect to the cocrystal product obtained. Reported in this work are the structures of five previously unreported caffeine cocrystals with monocarboxylic acids, including formic acid, acetic acid, and trifluoroacetic acid (05CGD2233). The structures were determined by powder and single crystal X-ray diffraction. 

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