The reaction of the bismuth silanolates [Bi(OSiR2R')3] (R = R' = Me, Et, iPr; R = Me, R' = tBu) with water has been studied. Partial hydrolysis gave polynuclear bismuth-oxo clusters whereas amorphous bismuth-oxo(hydroxy) silanolates were obtained when an excess of water was used in the hydrolysis reaction. The metathesis reaction of BiCl3 with NaOSiMe3 provided mixtures of heterobimetallic silanolates. The molecular structures of [Bi18Na4O20(OSiMe3)18] (2), [Bi33NaO38(OSiMe3)24].3 C7H8 (3.3 C7H8), [Bi50Na2O64(OH)2(OSiMe3)22].2 C7H8.2H2O (4.2 C7H8.2 H2O), [Bi4O2(OSiEt3)8] (5), [Bi9O7(OSiMe3)13].0.5 C7H8 (6. 0.5C7H8), [Bi18O18(OSiMe3)18)].2C7H8 (7. 2C7H8) and [Bi20O18(OSiMe3)24].3C7H8 (8.3C7H8) are presented and compared with the solid-state structures of [Bi22O26(OSiMe2tBu)14] (9) and beta-Bi2O3. Compound 2 crystallises in the triclinic space group P1 with the lattice constants a = 17.0337(9), b = 19.5750(14), c = 26.6799(16) A, alpha = 72.691(4), beta = 73.113(4) and gamma = 70.985(4) degrees ; compound 3.3C7H8 crystallises in the monoclinic space group P2(1)/n with the lattice constants a = 20.488(4), b = 22.539(5), c = 26.154(5) A and beta = 100.79(3) degrees ; compound 4.2C7H82 H2O crystallises in the monoclinic space group P2(1)/n with the lattice constants a = 20.0518(12), b = 24.1010(15), c = 27.4976(14) A and beta = 103.973(3) degrees ; compound 5 crystallises in the monoclinic space group P2(1)/c with the lattice constants a = 25.256(5), b = 15.372(3), c = 21.306(4) A and beta = 113.96(3) degrees ; compound 6.0.5C7H8 crystallises in the triclinic space group P1 with the lattice constants a = 15.1916(9), b = 15.2439(13), c = 22.487(5) A, alpha = 79.686(3), beta = 74.540(5) and gamma = 66.020(4) degrees ; compound 7.2C7H8 crystallises in the triclinic space group P1 with the lattice constants a = 14.8295(12), b = 16.1523(13), c = 18.4166(17) A, alpha = 75.960(4), beta = 79.112(4) and gamma = 63.789(4) degrees ; and compound 8.3C7H8 crystallises in the triclinic space group P1 with the lattice constants a = 17.2915(14), b = 18.383(2), c = 18.4014(18) A, alpha = 95.120(5), beta = 115.995(5) and gamma = 106.813(5) degrees . The molecular structures of the bismuth-rich compounds are related to the CaF2-type structure. Formally, the hexanuclear [Bi6O8]2+ fragment might be described as the central building unit, which is composed of bismuth atoms placed at the vertices of an octahedron and oxygen atoms capping the trigonal faces. Depending on the reaction conditions and the identity of R, the thermal decomposition of the hydrolysis products [Bi(n)O(l)(OH)(m-)(OSiR3)(3n-(2l-m))] gives alpha-Bi2O3, beta-Bi2O3, Bi12SiO20 or Bi4Si3O12.
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http://dx.doi.org/10.1002/chem.200500857 | DOI Listing |
Adv Sci (Weinh)
January 2025
Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul, 04107, Republic of Korea.
In the search for new ultraviolet (UV) nonlinear optical (NLO) materials, two novel cadmium mixed halide compounds, (NH)CdClF and (NH)CdBrF, are successfully synthesized via hydrothermal methods. These compounds crystallize in the noncentrosymmetric (NCS) space group, R32, and are composed of distorted octahedral [CdXF] (X═Cl or Br) units, which extend into a 3D framework. Remarkably, both compounds demonstrate strong second-harmonic generation (SHG) efficiencies-3.
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January 2025
Department of Nephrology, State Key Laboratory of Kidney Diseases, Beijing Key Laboratory of Kidney Disease Research, National Clinical Research Center for Kidney Diseases, Nephrology Institute of the Chinese People's Liberation Army, Chinese PLA General Hospital, Beijing, China.
Spaceflight-induced multi-organ dysfunction affects the health of astronauts and the safety of in-orbit flight. However, the effect of microgravity on the kidney and the underlying mechanisms are unknown. In the current study, we used a hindlimb unweighting (HU) animal model to simulate microgravity and employed histological analysis, ischemia-reperfusion experiments, renal ultrasonography, bioinformatics analysis, isometric force measurement, and other molecular experimental settings to evaluate the effects of microgravity on the kidneys and the underlying mechanisms involved in this transition.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich 8093, Switzerland.
We report spectroscopic and spectrometric experiments that probe the London dispersion interaction between -butyl substituents in three series of covalently linked, protonated -pyridines in the gas phase. Molecular ions in the three test series, along with several reference molecules for control, were electrosprayed from solution into the gas phase and then probed by infrared multiphoton dissociation spectroscopy and trapped ion mobility spectrometry. The observed N-H stretching frequencies provided an experimental readout diagnostic of the ground-state geometry of each ion, which could be furthermore compared to a second, independent structural readout via the collision cross section.
View Article and Find Full Text PDFDalton Trans
January 2025
Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, 48149 Münster, Germany.
The cadmium-rich intermetallic compounds RhCd ( = Ca, Sr, Y, La-Nd, Sm-Lu) were synthesized from the elements in sealed tantalum tubes. The elements were reacted in an induction furnace and the samples were post-annealed to increase phase purity and crystallinity. The RhCd phases crystallize with the cubic CeCrAl type structure, space group 3̄.
View Article and Find Full Text PDFThis paper sheds light on how spaces become contested sites for identity construction and negotiation to take place. Applying the Social Representations Approach, a qualitative study of 10 focus group discussions (n = 39), was conducted in Singapore, Malaysia and the UK to explore how, and why racialised identity construction changed in each socio-political context. The study challenged two underlying assumptions in social psychology: (1) that the meaning of the racialised category holds constant across time and space, and (2) there exists a pan-racial identification among Asian identities, for example, which at times allows for racialised categories to be manipulated as variables.
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