Crystalline Composition of Equine Urinary Sabulous Deposits

The composition and crystal morphology of 141 equine sabulous deposits were determined by infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The IR analysis revealed that all investigated deposits contained calcium carbonates (calcite, CaCO3, and/or vaterite, CaCO3) as major constituents; 42 samples were composed of calcite and vaterite, 33 of calcite, 18 of calcite/vaterite and calcium oxalate, and 17 of vaterite. The remaining specimens contained calcite/vaterite and other compounds (calcium phosphates, sulphate and/or oxalates and/or silica). The examination of 44 selected samples by means of SEM/EDX, revealed the characteristic morphology and elemental composition of the constituents of the sabulous deposits. Calcite crystals showed a typical spherical shape, as well as other less common rhombohedral habit. Vaterite displayed a flower or star appearance and also a mulberry shape. Less frequent was a spherular habit for vaterite resembling that of calcite. Elemental analysis of both calcite and vaterite crystals showed, besides calcium, varying proportions of magnesium and potassium. It is concluded that calcite and vaterite were mainly present in a substituted form. Calcium oxalate dihydrate crystals showed their characteristic bi pyramidal morphology. Calcium oxalate monohydrate crystals, which were less frequent, exhibited dumbbell or hour-glass shape

Contribution to the study of the structures of methyl derivatives of ammonia from spectroscopical data

The infra-red absorption spectra of the methylamines are given between 4500 and 400 K. The spectra of di- and trimethylamine were run for the first time; that of monomethyl-amine was revised. Using data on electron diffraction and assuming that in the replacement of hydrogen in ammonia by methyl groups, the ammonia molecule suffers little change, the symmetry C8 is assumed for the mono- and dimethylamine and C3v for the trimethylamine. On this basis we assign the normal modes of vibration of these molecules to the experimental frequencies measured in the Raman and infra-red spectra. We have compared the frequencies for the bond C-H, N-H, and C-N in the compounds studied. Also, the force constants for N-H and C-N have been calculated for the amines studied on the valence force hypothesis. © 1956.Peer Reviewe

Infra-red C=O band intensity of acetic acid derivatives and chemical reactivity

Trabajo financiado por U.S. Department of Army. Número de contrato DR-91-508-EUC-357. Final technical report number 1, july 1958-july 1959Peer reviewe

Structure and composition of canine urinary calculi

The chemical constituents of 171 specimens of canine urinary calculi have been analysed by infrared spectroscopy. The analysis revealed that 46 per cent of the total contained struvite as the major component; 26 per cent contained cystine; 16 per cent were found to be composed of whewellite and, or, weddellite; 8 per cent of urates; 3 per cent of calcium phosphate (apatite and, or, brushite) and 1 per cent of silica. A series of selected samples was also studied by scanning electron microscopy and energy dispersive X-ray analysis (EDAX). This examination revealed structures similar to human stones. Potassium and complex urates containing two or more cations were commonly found in many areas of ammonium orate and sodium urate calculi. Moreover, EDAx analysis detected a calcium enriched urate in several zones of urate calculi. © 1990.Peer Reviewe

Structural and conformational study of 3-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9α-ol

The infrared, 1H and 13C nmr spectra of 3-methyl-2,4-diphenyl-3-azabicyclo[3.3.1]nonan-9α-ol (II) have been examined in several media. To assist in interpretation of the spectroscopic data, the crystal structure has been determined by X-ray diffraction. The bicyclic system adopts a flattened chair-chair conformation. The methy, phenyl and OH groups are in equatorial position with respect to the piperidine ring. The crystal structure is stabilized by means of O-H...O intermolecular hydrogen bonding. © 1993.Peer Reviewe

Potassium in sodium urate calculi

Peer reviewe

Structural study of methyl 2,6‐diphenyl‐N‐methyl‐4‐oxopiperidine‐3,5‐dicarboxylate enolic forms

The methyl 2,6-diphenyl-1-methyl-4-oxopiperidine-3,5-dicarboxylates 1 were synthesized by the Mannich procedure from methyl 3-oxoglutarate, benzaldehyde and methylamine. Keto-enol tautomerism as well as configurational isomerism at C-2 were observed. The stereochemistry of the Ib and Ic enolic forms were determined by H and C nmr data. Copyright © 2013 HeteroCorporation.Comisión Interministerial de la Ciencia y la Energía. Grant Number: FAR-044

Spectral properties and isomerism of nitroenamines. Part 1. 3-Amino-2-nitro-acrylic esters

8 páginas.3-Amino-2-nitroacrylic esters (1) with primary and secondary amino group crystallize either in the s-cis,Z(1A), the s-trans,Z(1B), or the s-cis,E(1C) isomeric forms, and in solution they exist as equilibrium mixtures of the three forms, in ratios strongly dependent on the polarity of the solvent. Each isomeric form has easily distinguishable i.r. absorptions. On the other hand, their 1H and 13C n.m.r. spectra show signals due to the s-cis,E from (1C), and a second set of signals attributed to the two rapidly interconverting conformations (1A and B) of the Z isomer.Peer reviewe

Synthesis and structural and conformational study of 3,7-dimethyl-3,7-diazabicyclo[3.3.1]nonan-9-one oxime and its tautomer imine N-oxide

In an attempt to synthesize the 3,7-dimethyl-3,7-diazabicyclo[3.3.1]nonan-9-one oxime hydrochloride, the corresponding tautomer imine N-oxide hydrochloride (I·HCl) was obtained, as deduced from X-ray and IR data. By neutralization of I·HCl, the corresponding oxime (II) was obtained and characterized by IR data. From the 1H and 13C NMR spectra of I·HCl and II, a twin-chair conformation for the bicyclic system, more flattened in II, was deduced. This conformation has also been shown by X-ray data for I·HCl. © 1994.Peer Reviewe