Chemistry & Earth Sciences: المرسلات الحديثة
السجلات المعروضة 541 -- 560 من 614
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Spectroscopic investigation of the novel charge-transfer complex [(phen)(TCNE)12] formed in the reaction of phenacetin with tetracyanoethylene
( Elsevier , 2005 , Article)The charge-transfer (CT) interaction of the electron donor phenacetin (phen) and the π-electron acceptor tetracyanoethylene (TCNE) has been studied in CH2Cl2. The results obtained indicate the formation of the novel ... -
Spectrophotometric and thermal studies on the charge – Transfer complexes of 4-(aminomethyl) piperidine as donor with σ- and π-electron acceptors
( Elsevier , 2014 , Article)The spectroscopic characteristics of the solid charge-transfer molecular complexes (CT) formed in the reaction of the electron donor 4-(aminomethyl) piperidine (4AMP) with the σ-acceptor iodine and the π-acceptors ... -
Constituents of Plants Growing in Qatar, Part XXX: A New Iridoid from Cistanche Phelypaea (L) COUT
(1995 , Article)New iridoid named phelypaeside (1) was isolated from the dried aerial parts of Cistanche phelypae (Orobanchaceae) growing in Qatar -
Chemical survey of some plants Growing in Qatar
(1989 , Article)Fifty one plants growing in Qatar, belonging to thirty families, were surveyed for alkaloids, anthraquinones, coumarins, flavonoids, tannins and saponins. The medicinal uses of these plants arereported. -
Constituents of Plants Growing in Qatar, Part XXVI: Phytochemical investigation of Rumex vesicarius
(1995 , Article)The study of Rumex vesicarius revealed the isolation and identification of four anthraquinones (chrysoplanol (I), emodin (II), physcion (III) and rhein (IV) and seven flavonoids (apigenin (V), isoorientin (VI), isovitesin ... -
Constituents of Plants Growing in Qatar, Part XXXI: Lipid constituents of seventeen range plants growing in Qatar
(2002 , Article)A preliminary study on the nutritive values of 17 Qatari range plants -
Novel charge transfer complexes of the donor 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane and the acceptors iodine, TCNE, and TCNQ
( Elsevier , 2011 , Article)Abstract Novel charge transfer complexes have been formed in the reaction of the interesting powerful electron donor 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane (HMHACOD) with σ-electron acceptor iodine ... -
Triterpenoids from Salvia aegyptiaca
(1993 , Article)Newly isolated secondary metabolites from Salvia aegyptiaca growing in Qatar -
Fatty acid composition of twelve algae from the Coastal Zones of Qatar
( Kluwer Academic Publishers , 1997 , Article)Fatty acid composition of twelve algal species from two different classes were determined. Three Chlorophyta species(Axetabularia calyxulux, Cladophors sericoides and Dictyosphaeria cavernosa) and nine Phaephyta species ... -
Flavonoids from Centaurea sinaica
(1992 , Article)Four Newly isolated flavonoids from Centaurea sinaica -
(−)-Paniculatol, a new ent-labdane bromoditerpene from Laurencia paniculata
( Elsevier Science Ltd. , 1997 , Article)(−)-Paniculatol, 1, an unusual tricyclic bromoditerpene belonging to the ent-labdane series has been identified in the red alga Laurencia paniculata collected on Qatari coasts, Arabian Gulf. The structure displays an unusual ... -
Major sterol composition of some algae from Qatar
( Elsevier Science Ltd. , 1995 , Article)Thirteen macroscopic algae belonging to the three main divisions Chlorophyceae, Rhodophyceae and Phaeophyceae from the coast of Qatar (Arabian Gulf) were investigated for their sterol composition by using GC-MS coupling ... -
Guaianolides from Centaurea sinaica
( Elsevier , 1990 , Article & Report)Three sesquiterpene lactones were isolated from the aerial parts of Centaurea sinaica: amberboin, chlorohyssopifolin A and sinaicin. The latter is reported for the first time. -
Phospholipid fatty acid composition of nine marine sponges from Qatar
( IFREMER , 1998 , Conference)Phospholipid fatty acid composition was studied in sponge from Qatar including eight Demospongia and one Calcarea. More than 60 fatty acids were identified in each species as methyl esters and N-acyl pyrrolidides by gas ... -
Charge-transfer complexes of 4-methylpiperidine with σ- and π-acceptors
( Elsevier , 2015 , Article)The solid charge-transfer (CT) molecular complexes formed in the reaction of the electron donor 4-methylpiperidine (4MP) with the σ-electron acceptor iodine and π-acceptors 7,7,8,8-tetracyanoquinodimethane (TCNQ), ... -
Guaianolides from Picris radicata
( Elsevier Science Ltd. , 1996 , Article)The methylene chloride-methanol (1:1) extract of the aerial parts of Picris radicata Forssk afforded two new guaianolides. The structures were established from spectral data. -
Loading Rates of Dust and Metals in Residential Houses of Arid and Dry Climatic Regions
( Taiwan Association for Aerosol Research , 2016 , Article)Dust samples were collected from 38 naturally ventilated houses for 12 weeks. Effects of three variables in two groups each were evaluated: proximity to traffic density (main- and side-roads), cigarettes smoking (smoking ... -
Mechanism and kinetics of electrochemical degradation of uric acid using conductive-diamond anodes
( Taylor & Francis , 2016 , Article)Uric acid (UA) is one of the principal effluents of urine wastewaters, widely used in agriculture as fertilizer, which is potentially dangerous and biorefractory. Hence, the degradation of UA (2,6,8-trihydroxy purine) in ... -
Aldehyde dehydrogenase expression in Metaphire posthuma as a bioindicator to monitor heavy metal pollution in soil
( BioMed Central , 2016 , Article)Background Soil contamination and associated pollution plays a detrimental role in soil flora and fauna. Soil is processed and remodeled by subterranean earthworms, accordingly are referred to as soil chemical engineers. ... -
Crystal structure of (E)-2-{[(6-methoxy-1,3-benzothiazol-2-yl)imino]methyl}phenol
( International Union of Crystallography , 2015 , Article)The title compound, C15H12N2O2S, crystallizes in the orthorhombic space group Pna21, with two molecules in the asymmetric unit (Z′ = 2). Each molecule consists of a 2-hydroxy Schiff base moiety linked through a spacer ...
