ethanolic crude extract of i. imbricata lindl. (iridaceae) was subjected to column chromatography on silica gel with varying portions of meoh: chcl3. nigicin (irisolone) was isolated and its identification carried out by ir, uv, ms, 1-d and 2-d nmr spectroscopy.

4-n- prophyl- 1,2,4- triazoline-3-5- dione was synthesized from n-propylisocyanate and ethylhydrazine carboxylate in several steps. the title compound was isolated as pink crystals in high yield and purity. this compound was fully characterized by ir and h-nmr spectroscopy

3-(2-furanyl)-2-propenoic acid has been used to prepare a new series of organotin complexes of general formula r3snl (r=me, et, n-bu, ph and cy) and r2snl2 (r=me and n-bu). these complexes have been characterized by elemental analyses, ir, 1h-nmr, mass and mössbaure spectroscopy.

A new selection procedure of an informative near-infrared (NIR) region for regression model building is proposed that uses an online NIR/mid-infrared (mid-IR) dual-region spectrometer in conjunction with two-dimensional (2D) NIR/mid-IR heterospectral correlation spectroscopy. In this procedure, both NIR and mid-IR spectra of a liquid sample are acquired sequentially during a reaction process u...

Sulfur hexafluoride (SF₆) gas-insulated electrical equipment is widely used in high-voltage (HV) and extra-high-voltage (EHV) power systems. Partial discharge (PD) and local heating can occur in the electrical equipment because of insulation faults, which results in SF₆ decomposition and ultimately generates several types of decomposition products. These SF₆ decomposition products can be qualit...

Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributi...

Nanoscale materials with size smaller than the characteristic domain size could simplify the domain structure and uncover the intrinsic properties in detail. Herein, a ultrafast open space calcination pathway is first put forward to synthesize high-quality single-domain VO(2)(M) nanocrystals and an in situ variable-temperature IR spectroscopy is first proposed to identify the size-dependent MIT...

We investigated the characteristics of the thiocyanate (SCN) functional group as a probe of local structural dynamics for 2D-IR spectroscopy of proteins, exploiting the dependence of vibrational frequency on the environment of the label. Steady-state and time-resolved infrared spectroscopy are performed on the model compound methylthiocyanate (MeSCN) in solvents of different polarity, and compa...

Fourier Transform Infrared (FT-IR) spectroscopy is a robust method for macromolecular analysis and differentiation of microorganisms. However, most studies are performed in controlled conditions and it is unclear whether this tool is appropriate for the identification of eukaryotic microalgae species from variable environments. In order to address this, nine closely-related species of marine an...

Weak pi hydrogen-bonded solute/solvent complexes are studied with ultrafast two-dimensional infrared (2D-IR) vibrational echo chemical exchange spectroscopy, temperature-dependent IR absorption spectroscopy, and density functional theory calculations. Eight solute/solvent complexes composed of a number of phenol derivatives and various benzene derivatives are investigated. The complexes are for...