38 research outputs found
2-(3,5-Di-tert-butyl-4-hydroxybenzylsulfanyl)-N′-(3-methoxybenzylidene)acetohydrazide
The title compound, C25H34N2O3S, is a derivative of N′-benzylideneacetohydrazide having substituents on the acetyl and benzylidenyl parts, and displays a planar Ccarbonyl—NH—NCanisyl fragment [torsion angle = 174.9 (3)°]. The –NH– unit forms an N—H⋯O hydrogen bond with the carbonyl O atom of an inversion-related molecule
2-(3,5-Di-tert-butyl-4-hydroxybenzylsulfanyl)nicotinic acid
Two molecules of the title compound, C21H27NO3S, are disposed about a center of inversion, generating an O—H⋯O hydrogen-bonded dimer
2-(1,3-Benzoxazol-2-ylsulfanyl)-1-phenylethanone
In the title compound, C15H11NO2S, a new thio-benzoxazole derivative, the dihedral angle between the benzoxazole ring and the phenyl ring is 9.91 (9)°. An interesting feature of the crystal structure is the short C⋯S [3.4858 (17) Å] contact, which is shorter than the sum of the van der Waals radii of these atoms. In the crystal structure, molecules are linked together by zigzag intermolecular C—H⋯N interactions into a column along the a axis. The crystal structure is further stabilized by intermolecular π–π interactions [centroid–centroid = 3.8048 (10) Å]
Di-n-butylammonium 2-(3,5-di-tert-butyl-4-hydroxybenzylsulfanyl)nicotinate
The asymmetric unit of the title compound, C8H20N+·C21H26NO3S−, contains two indpendent ion pairs which are disposed about a psuedo-inversion center, generating an ammonium–carboxylate N—H⋯O hydrogen-bonded four-component cluster. In the crystal structure, adjacent clusters are linked by hydroxy–carboxylate O—H⋯O hydrogen bonds, forming a chain
2-(1,3-Benzothiazol-2-ylsulfanyl)-1-phenylethanone
In the molecule of the title compound, C15H11NOS2, the 1,3-benzothiazole ring is oriented at a dihedral angle of 6.61 (6)° with respect to the phenyl ring. In the crystal structure, intermolecular C—H⋯O interactions link the molecules in a herring-bone arrangement along the b axis and π–π contacts between the thiazole and phenyl rings [centroid–centroid distance = 3.851 (1) Å] may further stabilize the structure
4-Chloro-2-[(E)-2-(4-methoxyphenyl)ethyliminomethyl]phenol
In the title Schiff base, C16H16ClNO2, the 2-(4-methoxyphenyl)ethyl (CH3OC6H4CH2CH2–; r.m.s. deviation = 0.10 Å) and 4-chloro-2-(iminomethyl)phenol (N=CHC6H3ClOH; r.m.s. deviation = 0.01 Å) portions are both essentially planar, the two parts being inclined at an angle of 61.8 (1)°. The hydroxy group forms a hydrogen bond to the imino N atom
N′-[(Biphenyl-4-yl)methylene]-2-[(3,5-di-tert-butyl-4-hydroxybenzyl)sulfanyl]acetohydrazide
In the title compound, C30H36N2O2S, the dihedral angle between the two aromatic rings of the biphenyl residue is 31.2 (1)°. The two methylene C atoms subtend an angle of 99.9 (1)° at the S atom. In the crystal, molecules form inversion dimers linked by pairs of N—H⋯O hydrogen bonds. The hydroxyl group is shielded by the tert-butyl residues and is therefore not involved in any hydrogen bonding
Emission of short-lived halocarbons by three common tropical marine microalgae during batch culture
Very short-lived halocarbons of marine biogenic origin play an important role in affecting tropospheric and stratospheric chemistry. In recent years, more attention has been paid to tropical regions where the influence of strong convective forces is responsible for rapid uplifting of the volatile organohalogens from the open surface waters into the atmosphere. This laboratory-based study reports on three common tropical marine microalgae capable of emitting a range of short-lived halocarbons, namely, CH3I, CHBr3, CH2Br2, CHBr2Cl, and CHCl3. Chlorophyll a and cell density were highly correlated to the quantity of all five compounds emitted (p < 0.01). The diatom Amphora sp. UMACC 370 had a higher range of CH3I emission rate (10.55–64.18 pmol mg−1 chl a day−1, p < 0.01) than the cyanobacterium Synechococcus sp. UMACC 371 and chlorophyte Parachlorella sp. UMACC 245 (1.04–3.86 pmol mg−1 chl a day−1 and 0–2.16 pmol mg−1 chl a day−1, p < 0.01, respectively). Furthermore, iodine was the dominant halogen emitted in terms of total combined halide mass of all three species. Overall, the emissions of short-lived halocarbons were both species- and growth phase-dependent, highlighting the importance of considering cell physiological conditions when determining gas emission rates
Pheophorbide b ethyl ester from a chlorella vulgaris dietary supplement
In the title compound, C37H38N4O6, four five-membered nitrogen-bearing rings are nearly coplanar. Two N atoms in two these five-membered rings have attached H atoms, which contribute to the formation of intramolecular N—H⋯N hydrogen bonds [N⋯N = 2.713 (5)–3.033 (6) Å]
Pyrolytic–deoxygenation of triglyceride via natural waste shell derived Ca(OH)2 nanocatalyst
Cracking–Deoxygenation process is one of the important reaction pathways for the production of biofuel with desirable n-C17 hydrocarbon chain via removal of oxygen compounds. Calcium-based catalyst has attracted much attention in deoxygenation process due its relatively high capacity in removing oxygenated compounds in the form of CO2 and CO under decarboxylation and decarbonylation reaction, respectively. In the present study, deoxygenation of triolein was investigated using Ca(OH)2 nanocatalyst derived from low cost natural waste shells. The Ca(OH)2 nanocatalyst was prepared via integration techniques between surfactant treatment (anionic and non-ionic) and wet sonochemical effect. Results showed that sonochemically assisted surfactant treatment has successfully enhanced the physicochemical properties of Ca(OH)2 nanocatalyst in terms of nano-particle sizes (∼50 nm), high surface area (∼130 m2 g−1), large porosity (∼18.6 nm) and strong basic strength. The presence of superior properties from surfactant treated Ca(OH)2 nanocatalysts rendered high deoxygenation degree, which are capable of producing high alkane and alkene selectivity in chain length of n-C17 (high value of C17/(n-C17 + n-C18) ratio = 0.88). Furthermore, both Ca(OH)2–EG and Ca(OH)2–CTAB nanocatalysts showed high reactivity with 47.37% and 44.50%, respectively in total liquid hydrocarbon content of triolein conversion with high H/C and low O/C ratio