formation of non bonded organic layer around inorganic particles like iron sulfide and zeolites, was hypothesized as starting point for one of the possible mechanisms of the origin of life on earth. in this study, the general circumstances needed for creation of such organic layer was investigated. an aliphatic hydrocarbon (hexane), an aromatic hydrocarbon (toluene), an alcohol (n-octanol) and ...

In the tetranuclear centrosymmetric title compound, [Pb(4)(NO(3))(8)(C(11)H(10)N(2))(4)], irregular PbN(2)O(5) and PbN(2)O(4) coordination polyhedra occur. The hepta-coordinated lead(II) ion is bonded to two bidentate and one monodentate nitrate ion and one bidentate 6-methyl-2,2'-bipyridine (mbpy) ligand. The six-coordinate lead(II) ion is bonded to one bidentate and two monodentate nitrate an...

Silica-bonded N-propyldiethylenetriamine sulfamic acid (SPDTSA) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines  through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines  at room temperature under solvent-free conditions. SPDTSA showed much the same efficiency when used in con...

Brønsted acidic ionic liquid triethylamine-bonded sulfonic acid {[Et3N-SO3H]Cl} efficiently catalyzes the one-pot multi-component condensation of 2-naphthol with arylaldehydes and dimedone (5,5-dimethylcyclohexane-1,3-dione) under solvent-free conditions to afford 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-ones in high yields and relatively short reaction times.

The one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by tandem Knoevenagel-Michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid catalyst was reported. SBPPSA showed much the same efficiency when used in consecutive reaction runs.

Formation of non bonded organic layer around inorganic particles like iron sulfide and zeolites, was hypothesized as starting point for one of the possible mechanisms of the origin of life on earth. In this study, the general circumstances needed for creation of such organic layer was investigated. An aliphatic hydrocarbon (hexane), an aromatic hydrocarbon (toluene), an alcohol (n-octanol) and ...

many modern analytical methods deal with the trace-level determination of compounds of interest in highly complex environmental samples by means of chromatographic techniques. the introduction of a “clean” sample into an analytical instrument can make analyses easier and prolongs the equipment life. the use of solid-phase extraction (spe) has grown and is a fertile technique of sample preparati...

X-ray absorption spectroscopy and x-ray Raman scattering were used to probe the molecular arrangement in the first coordination shell of liquid water. The local structure is characterized by comparison with bulk and surface of ordinary hexagonal ice Ih and with calculated spectra. Most molecules in liquid water are in two hydrogen-bonded configurations with one strong donor and one strong accep...

One of the fundamental attributes a liquid chromatography column is its stability when exposed to acidic and basic mobile phases. However, there have been relatively few reports date on hydrophilic interaction (HILIC) columns. Here, we report results evaluations carried out for HILIC columns packed with ethylene-bridged hybrid or silica particles using accelerated conditions, employing 100% aqu...