Precise Nuclear Quadrupole Moments of 8B and 13B

The electric quadrupole coupling constants eqQ/h of ⁸B (, T _1/2 = 769 ms) and ¹³B (, T _1/2 = 17.4 ms) in single crystal TiO₂ have been precisely measured by the β-NQR technique. The ratios of these Q moments to Q(¹²B) were determined as ∣Q(⁸B)/Q(¹²B)∣ = 4.882(32) and ∣Q(¹³B)/Q(¹²B)∣ = 2.768(24).     

Hyperfine fields in Fe crystal detected by β-emitting12N

Hyperfine magnetic fields in a single crystal Fe were measured by use of asymmetric decay and NMR detection of spin polarized -emitting¹²N.     

Sulfur nitride in organic chemistry. 6. Preparation of 3,4-disubstituted 1,2,5-thiadiazoles by the reaction of sulfur nitride with acetylenes

The reaction of sulfur nitride (1) with acetylenes (2a-m) was carried out in refluxing toluene to give 1,2,5-thiadiazoles (3a-m) as a major product.     

Precise measurement of the magnetic moment of doubly closed shell − 1 nucleon nucleus15O(I π1/2−,T 1/2=122 s)

The magnetic moment of¹⁵O(I=1/2^–,T _1/2=122 s) has been measured precisely by use of the -NMR detection of¹⁵O in TiO₂ as, |(¹⁵O; 1/2^–)|=0.71951 (12) µ_N. The effective nucleon mass in the nuclei around mass number 16 was discussed using the isoscalar moment deduced in connection with the magnetic moment of¹⁵N.     

New determination of quadrupole coupling constants of Li isotopes in single crystals LiIO3 andLiNbO3

Quadrupole effects in NMR spectra of⁸Li(I =2⁺;T _1/2=0.84 s) in LiIO₃ andLiNbO₃ single crystals have been detected by use of a modified -NMR. The coupling constants for both crystals are in agreement with known ones. Field gradients in the crystals were measured by detecting pulsed-Fourier transformed NMR of⁷Li. The quadrupole moments deduced from both samples agree, and|Q(⁸Li; 2⁺)|=32.7±0.6 mb has been determined.     

NMR line width of12B in Pt detected by β-NMR

NMR spectra of¹²B in Pt (fcc) metal were observed by use of the -NMR detection method. A sharp single line was observed by use of an annealed Pt foil for the implantation medium. The dipolar broadening has been determined to be 332±30 Hz (HWHM).     

Development of a laser ablation-hollow cathode glow discharge emission source and the application to the analysis of steel samples.

A novel atomic emission spectrometry comprising laser ablation as a sampling source and hollow cathode plasma for the excitation of ablated sample atoms is proposed. In this arrangement, a conventional Grimm-type discharge lamp is employed, but the polarity of the power supply is reversed so that the cylindrical hollow tube acts as a cathode and the glow discharge plasma is produced within this tube. A laser is irradiated to introduce sample atoms into the discharge plasma. Ablated atoms are excited by collisions with electrons and gas species, and emit characteristic radiation upon de-excitation. The experiments were conducted only in an atmosphere of helium gas so as to avoid a rapid erosion of the cathode hollow tube. Phase-sensitive detection with a lock-in amplifier was utilized to reject the continuous background emission of the plasma gas and emissions of sputtered atoms from the tube material. The unique feature of this technique is that the sampling and excitation processes can be controlled independently. The proposed technique was employed for the determination of Cr, Mn, and Ni in low-alloyed steel samples. The obtained concentrations are in good agreement with the reported values. The relative standard deviation (RSD), a measure of the analytical precision, was estimated to be 2-9% for Cr, 3-4% for Mn, and 4-11% for Ni determination.     

Triarylation of eta 6-dihydronaphthalene-Cr(CO)3 complexes

With ease, eta 6-dihydronaphthalene tricarbonylchromium(0) complexes undergo a triple arylation with concomitant ring closure, when submitted to Heck reactions under 'Jeffery conditions'.     

Condensation reaction of 3,4-dibenzoyl-1-methyl-2,5-diphenylpyrrole and -1-phenylpyrazole with methylamine derivatives affording pyrrolo [3,4-c]pyridine and 2H-pyrazolo[3,4-c]- and [4,3-c]pyridines

The reaction of 3,4-dibenzoyl-1-methyl-2,5-diphenylpyrrole ( 1 ) and -1-phenylpyrazole ( 2 ) with methylamines ( 3a-c ) afforded pyrrolo[3,4-c]pyridine ( 4 ), and isomeric 2H-pyrazolo[3,4-c]pyridines ( 5a-c ) and [4,3-c]pyridines ( 6a-c ), respectively.     

Hyperfine interactions of short-lived β-emitter 8Li in ferromagnetic Ni

Hyperfine interactions of ⁸Li impurity nucleus imbedded in ferromagnetic Ni metal were studied using the β-NMR technique. Two kinds of hyperfine fields B₈₂ were found, corresponding to two different final sites of Li atoms in the Ni lattice. The nuclear spin-lattice relaxation times T₁ of ⁸Li in Ni were also determined for each field. Temperature dependencies of B₈₂ and T₁ were observed to deduce these values at T=0 K that can be compared with those calculated recently by Akai et al. This revised version was published online in August 2006 with corrections to the Cover Date.