Mass spectral fragmentation pattern of 2,2′-bipyridyls. Part II. 5-Hydroxy- and 5-alkoxy-2,2′-bipyridyls

The mass spectra of 5-hydroxy-, 5-methoxy-, 5-ethoxy- and 5-propoxy-2,2′-bipyridyls are reported. The fragmentation proposals are supported by high resolution mass measurements and metastable transitions.     

Mass spectral fragmentation pattern of 2,2′-bipyridyls. Part XII. 2,2′-Selenodipyridine

The mass spectrum of 2,2′-selenodipyridine obtained by electron impact is reported. The base peak in the spectrum is due to the C₅H₄N⁺ ion formed principally by rupture of the central bonds. The molecular ion gives rise to a peak of 50% of the intensity of the base peak. Other fragmentations include loss of H, Se and CSe from the molecular ion and HCN from the M-1 ion.     

Mass spectral fragmentation pattern of 2,2′-bipyridyls Part XI. 2,2′-Iminodipyridine

The base peak in the mass spectrum of 2,2′-iminodipyridine is due to the M-1 ion. There are several minor fragmentation routes from the molecular ion but the principal pathway involves rupture of the central bonds. J. Heterocyclic Chem., 14, 1103 (1977)     

Synthesis,polarography and herbicidal activity of quaternary salts of 2-(4-pyridyl)-1,3,5-triazines, 5-(4-pyridyl)pyrimidine, 2-(4-pyridyl)pyrimidine and related compounds

2-(4-Pyridyl)-1,3,5-triazine, 2-(4-pyridyl)-4-methyl-1,3,5-triazine, 2-(4-pyridyl)-4,6-dimethyl-1,3,5-triazine and 2-(4-pyridyl)pyrimidine have been prepared by modification of established triazine and pyrimidine syntheses. These compounds and some of their relatives have been converted to quaternary pyridinium salts. The polarographic reduction potentials of the salts in aqueous solution are pH dependent. The activity of the salts as post-emergent herbicides is reported.     

Mass spectral fragmentation pattern of 2,2′-bipyridyls Part IV. Di-2-pyridly ketone

The fragmentation of di-2-pyridyl ketone on electron impact involves elimination of neutral CO from the molecular ion and rearrangement to the 2,2′-l>ipyridyl molecular ion in addition to rupture of the central bonds to form C₅H₄N⁺ and C₆H₄NO⁺ ions.     

Quantitative characterization of nanoparticle agglomeration within biological media

The electronics industry is one of the world??s fastest growing manufacturing industries. However, e-waste has become a serious pollution problem. This study reports the recovery of e-waste for preparing valuable MCM-48 and ordered mesoporous carbon for the first time. Specifically, this study adopts an alkali-extracted method to obtain sodium silicate precursors from electronic packaging resin ash. The influence of synthesis variables such as gelation pH, neutral/cationic surfactant ratio, hydrothermal treatment temperature, and calcination temperature on the mesophase of MCM-48 materials is investigated. Experimental results confirm that well-ordered cubic MCM-48 materials were synthesized in strongly acidic and strongly basic media. The resulting mesoporous silica had a high surface area of 1,317?m²/g, mean pore size of about 3.0?nm, and a high purity of 99.87?wt%. Ordered mesoporous carbon with high surface area (1,715?m²/g) and uniform pore size of CMK-1 type was successfully prepared by impregnating MCM-48 template using the resin waste. The carbon structure was sensitive to the sulfuric acid concentration and carbonization temperature. Converting e-waste into MCM-48 materials not only eliminates the disposal problem of e-waste, but also transforms industrial waste into a useful nanomaterial.