2,6-Di-tert-butyl-4-(3-chloro-2-hy­droxy­prop­yl)phenol

In the title 2-propanol derivative, C17H27ClO2, the two tert-butyl groups both have one methyl C atom lying in the plane of the aromatic ring. In the crystal, the phenol group forms a hydrogen bond to the hy­droxy O atom belonging to the alkyl substituent of an adjacent mol­ecule, forming a chain along the ac diagonal. The Cl atom is disordered over two positions in a 0.73 (4):0.27 (4) ratio

1-(2-Oxo-3,4-dihydro-2H-1,3-benzoxazin-4-yl)urea monohydrate

The organic molecule in the title hydrate, C9H9N3O3·H2O, was obtained by the condenstation of salicylic aldehyde with urea in acetonitrile. The oxazine ring adopts a slightly distorted sofa conformation, with the N atom deviating from the plane passing through the other atoms of the ring by 0.267 (2) Å. The crystal structure displays inter­molecular N—H⋯O and O—H⋯O hydrogen bonding

In vitro evaluation of the marginal seal of four restoration materials on deciduous molars

The aim of this study was to compare the marginal microleakage of Fuji II LC (A), composite resin Z250 (B), Fuji IX GP (C), and Dyract AP (F) in class V cavities and at the Fuji II LC/Z250 (D) and Fuji IX GP/composite resin Z250 (E) interfaces of an open sandwich technique on deciduous teeth. After thermocycling the mean marginal dye penetration at the enamel junction was 21.6 microns +/- 14.2 for group A; 83.6 microns +/- 32.3 for group B; 7.5 microns +/- 7.5 for group C; 38.7 microns +/- 27.5 for group D, and 0 micron for groups E and F. Mean dye penetration at the cementum junction was 37.1 +/- 20.2 (A); 123 +/- 42.1 (B); 28.7 +/- 17.1 (C); 0 (D); 14.4 +/- 14.4 (E); and 0 (F) microns. No leakage was seen at the junction between Fuji II LC and Z250 (0 micron), whereas a mean leakage of 184 microns between Fuji IX and Z250 was measured. In enamel the best seal was obtained with Dyract AP, but with differences at the limit of significance (P = 0.07). Sealing was significantly worse with Z250 (p = 0.03 versus Fuji II LC; p = 0.006 versus Fuji IX GP; and p = 0.003 versus Dyract AP). In cementum, the comparison between the grouped data Z250-Fuji II LC versus Fuji IX GP-Dyract AP was highly significant (p 0.001), while there was no detectable difference between Z250 and Fuji II LC

4-[3-(Benzylamino)-2-hydroxypropyl]-2,6-di-tert-butylphenol

In the title compound, C24H35NO2, the planes of the two aromatic rings form a dihedral angle of 72.76 (4)°. In the crystal, molecules are linked by O—H...O and O—H...N hydrogen-bond interactions, forming an extended two-dimensional framework parallel to the ab plane

Halogen Bonding in the Decoration of Secondary Coordination Sphere of Zinc(II) and Cadmium(II) Complexes: Catalytic Application in Cycloaddition Reaction of CO2 with Epoxides

A.V.G. and K.T.M. thank FCT and Instituto Superior Técnico (DL 57/2016, L 57/2017 and CEEC Institutional 2018 Programs, Contracts no: IST-ID/110/2018 and IST-ID/85/2018). VAA is grateful to Associação do Instituto Superior Técnico para Investigação e Desenvolvimento for her research fellowship through grant no: BL110/2022-IST-ID. K.T.M. and A.V.G. acknowledge the support by the Baku State University (Azerbaijan). A.R.R. thanks the Erasmus Program of the University of Milan and the Instituto Superior Técnico for a traineeship at the IST. Authors thank the Portuguese NMR Network (IST-UL Centre) and the IST Node of the Portuguese Network of mass-spectrometry. NMR spectrometers are part of The National NMR Facility, supported by FCT (ROTEIRO/0031/2013-PINFRA/22161/2016) (co- financed by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC). Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.Three new zinc(II) complexes [Zn(H2L3)2(H2O)3] (Zn2), [Zn(H3L2a)(H2O)3]n (Zn3) (H3L2a = 2,4-diiodo-5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazineyl)isophthalate) and [Zn(HL4)(DMF)(H2O)]n (Zn4) were synthesized by the reaction of Zn(II) salts with 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl) isophthalic acid (H3L3), 2,4,6-triiodo-5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene)hydrazineyl) isophthalic acid (H5L2) (in the presence of NH2OH·HCl) and 5-(2-(2,4-dioxopentan-3-ylidene)hydrazineyl)-2,4,6-triiodoisophthalic acid (H3L4), respectively. According to the X-ray structural analysis, the intramolecular resonance-assisted hydrogen bond ring remains intact, with N···O distances of 2.562(5) and 2.573(5) Å in Zn2, 2.603(6) Å in Zn3, and 2.563(8) Å in Zn4. In the crystal packing of Zn3, the cooperation of I···O and I···I types of halogen bonds between tectons leads to a one-dimensional supramolecular polymer, while I···O interactions aggregate 1D chains of coordination polymer Zn4. These new complexes (Zn2, Zn3, and Zn4) and known [Zn(H3L1)(H2O)2]n (Zn1) (H3L1 = 5-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) hydrazineyl)isophthalate), {[Zn(H3L1)(H2O)3]·3H2O}n (Zn5), [Cd(H3L1)(H2O)2]n (Cd1), {[Cd(HL3)(H2O)2(DMF)]·H2O}n (Cd2), [Cd(H3L3)]n (Cd-3), {[Cd2(μ-H2O)2(μ-H2L4)2(H2L4)2]·2H2O}n (Cd4), and {[Cd(H3L1)(H2O)3]·4H2O}n (Cd5) were tested as catalysts in the cycloaddition reaction of CO2 with epoxides in the presence of tetrabutylammonium halides as the cocatalyst. The halogen-bonded catalyst Zn4 is the most efficient one in the presence of tetrabutylammonium bromide by affording a high yield (85-99%) of cyclic carbonates under solvent-free conditions after 48 h at 40 bar and 80 °C.publishersversionpublishe