Calculations show that the unexpected low phenyl migratory aptitude observed in reactions of mixed alkyl-aryl boranes with benzylic sulfur ylides can be attributed to (1) a conformational issue, (2) the reduction of the usual neighbouring effect of the phenyl in the transition state by the benzylic nature of the migrating terminus, (3) steric hindrance suffered by the larger phenyl group migrat...

Soil quality assessment is a significant approach for arable land, especially in a coastal region to gain a better understanding of soil productivity and effect of agricultural systems on soil resources. This study aimed to determine the quality of cultivated soil of both urban (Noakhali) and rural areas (Kabirhat and Subarnachar) of Noakhali, Bangladesh. The soil quality was evaluated as soil ...

The use of phosphoramidite ligands in the rhodium-catalyzed asymmetric conjugate addition of potassium organotrifluoroborates to various enones in the absence of water is described. A systematic search for effective catalysts has been performed by use of high-throughput screening methods. Initially, we have screened reaction conditions, catalyst precursors, and focused ligand libraries. In the ...

We report on measurements of the interstitial iron concentration in boron-doped crystalline silicon by measuring the dissociation rate of iron-boron pairs using a camera-based photoluminescence setup (dynamic Fei imaging). This approach enables us to identify the interstitial iron concentration without measuring absolute values of the carrier lifetime and without knowing the recombination prope...

The reactions of boron halides with free base porphyrins under conditions where partial hydrolysis of the boron halides can occur give diboron porphyrin complexes containing BOB moieties in which each boron is bonded to two porphyrin nitrogen atoms. BF(3).OEt(2) with H(2)(por) gives B(2)OF(2)(por) (por = tpp, ttp, tpClpp, oep) which has an asymmetric structure in which one boron lies in the por...

In the title dye compound, C(19)H(14)BF(7)N(2), the boron-dipyrromethene core lies on a crystallographic mirror plane which bis-ects the BF(2) and penta-fluoro-phenyl groups. The dihedral angle between the penta-fluoro-phenyl ring and the tricyclic system is thus 90° by symmetry. The sp(3)-hybridized B atom has a slightly distorted tetra-hedral coordination.

Boron exhibits anomalous diffusion during the initial phases of ion implant annealing. Boron transient enhanced diffusion is characterized by enhanced tail diffusion coupled with an electrically inactive immobile peak. The immobile peak is due to clustering of boron in the presence of excess interstitials which also enhance boron diffusion in the tail region. We present a simple model for the f...

Total boron concentrations in Drosophila changed during development and aging. The highest concentration of boron was found during the egg stage, followed by a decline during the larval stages. Newly emerged flies contained 35.5 ppm boron. During the adult stage the boron concentration increased by 52% by 9 weeks of age. Adding excess dietary boron during the adult stage decreased the median li...