The electrochemical reduction mechanism of 4′-nitrotricyanovinylhydrazone in DMF–B-R buffer to the corresponding [(4-hydroxyamino)phenyl]methamine <italic>via</italic> 2H<sup>+</sup>/2e<sup>−</sup> reduction of (<italic>E</italic>)-<italic>N</italic>-(1-(4-hydroxyamine)phenylethylidene)methamine is proposed.
Two independent mol-ecules, A and B, comprise the asymmetric unit of the title compound, C(21)H(18)N(2)OS, with the difference in the angle of orientation between the naphthalene ring system and the mean plane of the cyclo-heptyl ring [16.13 (1) in A and 11.48 (5)° in B], being evident. The cyclo-heptyl ring adopts a distorted chair conformation in each mol-ecule with r.m.s. deviations of 0.2345 (4) (A) and 0.2302 (4) Å (B). Intra-molecular O-H⋯N hydrogen bonding generates planar six-membered S(6) loops with r.m.s. deviations of 0.0099 (1) (A) and 0.0286 (1) Å (B).
Purpose The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices. Design/methodology/approach The poly(methyl methacrylate) (PMMA) and epoxy resin doped with photochromic spirobenzopyran were prepared and the effects of ultraviolet (UV) irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. Photochemical fatigue resistance of these films was also studied. Findings Irradiation of colourless 1′,3′,3′‐trimethyl‐6‐nitrospiro[2H‐1‐benzopyran‐2,2′‐indoline] spiropyran (SP) doped in PMMA and epoxy resin with UV light (366 nm) results in the formation of an intense purple‐red coloured zwitterionic photomerocyanine (PMC). The reverse reaction was photochemically induced by irradiation with white light. Photocolouration of SP doped in PMMA follows a first‐order rate equation ( k =0.0011 s −1 ), while that doped in epoxy resin deviates from linearity. It was found that photobleaching follows a first‐order equation in both matrices. The photobleaching rate constant of PMC in both matrices is the same and equals 0.0043 s −1 . Spirobenzopyran doped in PMMA shows better fatigue resistance than that doped in epoxy resin. Research limitations/implications The PMMA and epoxy resin polymers doped with photochromic spirobenzopyran described in the present paper were prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds. Practical implications The photochromic materials developed can be used for different applications, such as coatings and holography. Originality/value The method developed may be used to enhance the performance of photochromic materials.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The essential oil of Salvia aegyptiaca was analysed by GC/ MS technique. Eighteen compounds were identified. It was found that the essential oil comprises 40% terpenoidal constituents, opposite to 32% fat derivatives. The major terpenoidal component was 1(10)- aristolene (19.3%). From the non-volatile matter, ?-amyrin, lupeol, ?-sitosterol, stigmasterol, ?-sitosterol-?-D-glucopyranoside and stigmasterol-?-Dglucopyranoside as well as 3?-hydroxy-24-alkylcarboxylate-12- oleanan-28-oic acid. Fatty acids esters were isolated and identified by spectral means
This work presents the fabrication and investigation of the multiwalled carbon nanotubes (MWCNTs) and graphene pristine powders based multifunctional pressure, displacement and gradient of temperature sensors. The effect of pressure on the resistance, Seebeck coefficient , thermoelectric voltage and current of the sensors was measured by changing pressure from 0 to 1.65 kgf/cm2, while the effect of temperature gradient on the resistance, thermoelectric voltage and current of the sensors was measured up to the temperature gradient of 34–36°C. Dependence of the resistance on longitudinal compressive displacement up to 100 μm was investigated. It was found that the resistance, Seebeck coefficient and thermoelectric voltage of the CNT and graphene powders decreased with increasing pressure, while the thermoelectric current increased with pressure. Moreover, with increasing temperature gradient and average temperature a considerable increase was observed in thermoelectric current and voltage, while the increase in resistances was moderate. The increase in longitudinal displacement resulted in the compression of the samples that caused to decrease the resistances of the samples, especially in the case of samples made from CNT and graphene both. The simulation of the experimental results was carried out by using of linear functions and the results of simulations were in good agreement with experimental results.
A nanomaterial-based disposable immunosensor was developed for detection of phosphorylated protein using enzyme functionalization of carbon nanospheres as amplification labels.