322 research outputs found
Structure and Function of Synaptotagmin 1 C2 Domains as Determined by Site-Directed Spin Labeling
Synthesis of novel O-acylated-D-ribono-1,5-lactones and structural assignment supported by conventional NOESY-NMR and x-ray analysis
A practical method for the structural assignment of 3,4-O-benzylidene-D-ribono-1,5-lactones and analogues using conventional NMR techniques and NOESY measurements in solution is described. 2-O-Acyl-3,4-O-benzylidene-D-ribono-1,5-lactones were prepared in good yields by acylation of Zinner’s lactone with acyl chlorides under mildly basic conditions. Structural determination of 2-O-(4-nitrobenzoyl)-3,4-O-benzylidene-D-ribono-1,5-lactone was achieved by single crystal x-ray diffraction, which supports the results based on spectroscopic data.Este trabalho apresenta um método simples para a caracterização estrutural de 3,4-O-benzilideno-D-ribono-1,5-lactonas e análogos, fundamentado em técnicas convencionais de RMN e experimentos de NOESY em solução. 2-O-Acil-3,4-O-benzilideno-D-ribono-1,5-lactonas foram preparadas em bons rendimentos a partir da acilação das lactonas de Zinner empregando cloretos de ácido sob condições básicas. A estrutura de 2-O-(4-nitrobenzoil)-3,4-O-benzilideno-D-ribono-1,5-lactona foi determinada por difração de raios-X e confirmou, de forma inequívoca, os dados espectroscópicos obtidos.CNPq - MC
1-(o-Tolyl)thiourea
In the title compound, C8H10N2S, the o-tolyl group and the thiourea core are planar. The mean planes of the two groups are almost perpendicular [82.19 (8)°]. The thiourea group is in the thioamide form, in which resonance is present. In the crystal structure, molecules are linked by intermolecular N—H⋯S hydrogen bonds, forming two infinite chains parallel to the (110) and (10) planes
Different coordination modes for disulfoxides towards diorganotin(IV) dichlorides. X-ray crystal structures of 1,2-cis-bis-(phenylsulfinyl)ethene (rac-,cis-cbpse) and adducts [{Ph2SnCl2(meso-bpse)}n] and [{n-Bu2SnCl2(pdtd)}2]
The reactions of meso-1,2-bis(phenylsulfinyl)ethane (meso-bpse) with Ph2SnCl2, 2-phenyl-1,3-dithiane trans-1-trans-3-dioxide (pdtd) with n-Bu2SnCl2 and 1,2-cis-bis-(phenylsulfinyl)ethene (rac-,cis-cbpse) with Ph2SnCl2, in 1:1 molar ratio, yielded [{Ph2SnCl2(meso-bpse)}n], [{n-Bu2SnCl2(pdtd)}2] and [{Ph2SnCl2(rac,cis-cbpse)}x] (x = 2 or n), respectively. All adducts were studied by IR, Mössbauer and 119Sn NMR spectroscopic methods, elemental analysis and single crystal X-ray diffractometry. The X-ray crystal structure of [{Ph2SnCl2(meso-bpse)}n] revealed the occurrence of infinite chains in which the tin(IV) atoms appear in a distorted octahedral geometry with Cl atoms in cis and Ph groups in trans positions. The X-ray crystal structure of [{n-Bu2SnCl2(pdtd)}2] revealed discrete centrosymmetric dimeric species in which the tin(IV) atoms possess a distorted octahedral geometry with bridging disulfoxides in cis and n-butyl moieties in trans positions. The spectroscopic data indicated that the adduct containing the rac,cis-cbpse ligand can be dimeric or polymeric. The X-ray structural analysis of the free rac-,cis-cbpse sulfoxide revealed that the crystals belong to the C2/c space group.As reações de meso-1,2-bis(fenilsulfinil)etano (meso-bpse) com Ph2SnCl2, de 2-fenil-1,3-ditiona trans-1-trans-dióxido (pdtd) com n-Bu2SnCl2 e de 1,2-cis-bis-(phenylsulfinyl)ethene (rac-,cis-cbpse) com Ph2SnCl2, na proporção molar 1:1, levaram à formação de [{Ph2SnCl2(meso-bpse)}n], [{n-Bu2SnCl2(pdtd)}2] e [{Ph2SnCl2(rac,cis-cbpse)}x] (x = 2 ou n), respectivamente. Na investigação das propriedades estruturais dos produtos foram empregadas as espectroscopias de absorção no infravermelho, Mössbauer e RMN de 119Sn, além de análise elementar e difratometria de raios X em monocristal. O estudo de [{Ph2SnCl2(meso-bpse)}n] por difratometria de raios X revelou a ocorrência de um encadeamento infinito no qual os átomos de tin(IV) apresentam uma geometria octaédrica distorcida com os átomos de Cl em posições cis e os grupos Ph em trans. A estrutura cristalina de [{n-Bu2SnCl2(pdtd)}2] revelou a presença de espécies diméricas centrossimétricas nas quais os átomos de tin(IV) possuem geometria octaédrica distorcida com dissulfóxidos em ponte ocupando posições cis e grupos n-butila ocupando posições trans. Os dados espectroscópicos indicaram que o produto contendo o ligante rac,cis-cbpse pode ser dimérico ou polimérico. O estudo por difratometria de raios X do sulfóxido rac-,cis-cbpse livre revelou que os cristais pertencem ao grupo espacial C2/c.CNPqFAPESPFINE
Bis(tetraphenylphosphonium) tris[N-(methylsulfonyl)dithiocarbimato(2−)-κ2 S,S′]stannate(IV)
In the title complex, (C24H20P)2[Sn(C2H3NO2S3)3], the SnIV atom is coordinated by three N-(methylsulfonyl)dithiocarbimate bidentate ligands through the anionic S atoms in a slightly distorted octahedral coordination geometry. There is one half-molecule in the asymmetric unit; the complex is located on a crystallographic twofold rotation axis passing through the cation and bisecting one of the (non-symmetric) ligands, which appears thus disordered over two sites of equal occupancy. In the crystal structure, weak intermolecular C—H⋯O and C—H⋯S interactions contribute to the packing stabilization
Climate change adaptation cycle for pilot projects development in small municipalities: The northwestern Italian regions case study
More than half of the European population live in small and medium size municipalities, where climate adaptation planning is an under-researched topic within the climate change field. Many constraints might hinder the implementation of adaptation pilot projects due to lack of economic, knowledge, and technical available resources. Local institutions find difficulties in building a coherent local adaptation planning and design processes with international and national frameworks. In this context, this article proposes a methodology based on the available international frameworks to support the small communities with the aim to implement adaptation pilot projects within different sectors. In doing so, this paper tests a climate change adaptation cycle for pilot projects development in small municipalities; the first in Italy for small municipalities under 20.000 inhabitants. The proposed methodology could lead local adaptation initiatives in climate change risk assessment by supporting the research communities in developing a coherent vision for the local territories and to identify proper oriented measures to enhance demonstrative pilot projects and to increase the level of resilience in small municipalities, avoiding maladaptation
Low-temperature study of a new nevirapine pseudopolymorph
The title compound (systematic name: 11-cyclopropyl-4-methyl-5,11-dihydro-6H-dipyrido[3,2-b:2′,3′-e][1,4]diazepin-6-one butanol 0.3-solvate), C15H14N4O·0.3C4H9OH, was crystallized in a new triclinic pseudopolymorphic form, a butanol solvate, and the crystal structure determined at 150 K. The molecular conformation of this new form differs from that reported previously, although the main intermolecular hydrogen-bond pattern remains the same. N—H⋯O hydrogen bonds [N⋯O = 2.957 (3) Å] form centrosymmetric dimers and the crystal packing of this new pseudopolymorph generates infinite channels along the b axis
Weak C-H...Cl-Pd interactions toward conformational polymorphism in trans-dichloridobis (triphenylphosphane) palladium (II)
A new triclinic polymorph of the title compound, [PdCl2(C18H15P)2], has two independent molecules in the unit cell, with the Pd atoms located on inversion centres. One molecule has an eclipsed conformation, whereas the second molecule adopts a gauche conformation. The molecules with a gauche conformation are involved in weak intermolecular C-H...Cl-Pd interactions with symmetry-related molecules. It is suggested that C-H...Cl-Pd interactions are mainly responsible for the existence of conformational differences, which contribute to the polymorph formation. In the crystal, there are layers of eclipsed and gauche molecules separated by normal van der Waals interactions.FAPESP (09/08131-1)CNPqCAPESPROE
1-(2-Furoyl)-3-(o-tolyl)thiourea
The title compound, C13H12N2O2S, was synthesized from furoyl isothiocyanate and o-toluidine in dry acetone. The thiourea group is in the thioamide form. The central thiourea fragment makes dihedral angles of 2.6 (1) and 22.4 (1)° with the ketofuran group and the benzene ring, respectively. The molecular structure is stabilized by N—H⋯O hydrogen bonds. In the crystal structure, centrosymmetrically related molecules are linked by a pair of N—H⋯S hydrogen bonds to form a dimer with an R
2
2(6) ring motif
3D anthropometric investigation of head and face characteristics of Australian cyclists
Design specialists have acknowledged the need for more accurate measurements of human anthropometry through the use of 3D data, especially for the design of head and facial equipment. However, 3D anthropometric surveys of the human head are sparse in the literature and practically non-existent for Australia. Research published to date has not proposed concrete methods that can accurately address the hair thickness responsible for inaccurate representation of the head's shape. This study used a state-of-theart handheld white light scanner to digitize 3D anthropometric data of 222 participants in the Melbourne Metropolitan Area. The participants volunteered for the study consisted of 46 females and 176 males (age: 34.6 ± 12.5). The participants' head scans were aligned to a standard axis system, whereby a Hair Thickness Offset (HTO) method was introduced to more accurately describe the true shape of the head. It is envisaged that the database constructed through this research can be used as a reference for the design and testing of helmets in Australia
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