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Calcium silicate hydrates are members of a large family of minerals with layered structures containing pendant CaOH and SiOH groups that interact with confined water molecules. To rationalize the impact of the local chemical environment on the dynamics of water, SiOH‐ and CaOH‐rich model nanocrystals were synthesized by using the continuous supercritical hydrothermal method and then systematically studied by a combination of spectroscopic techniques. In our comprehensive analysis, the ultrafast relaxation dynamics of hanging hydroxy groups can be univocally assigned to CaOH or SiOH environments, and the local chemical environment largely affects the H‐bond network of the solvation water. Interestingly, the ordered "ice‐like" solvation water found in the SiOH‐rich environments is converted to a disordered "liquid‐like" distribution in the CaOH‐rich environment. This refined picture of the dynamics of confined water and hydroxy groups in calcium silicate hydrates can also be applied to other water‐containing materials, with a significant impact in many fields of materials science. [ABSTRACT FROM AUTHOR]

Three related series of peri-substituted bis(tellurides) bearing naphthalene, acenaphthene and acenaphthylene backbones (Nap/Acenap/Aceyl(TeY)2 (Nap=naphthalene-1,8-diyl N; Acenap=acenaphthene-5,6-diyl A; Aceyl=acenaphthylene-5,6-diyl Ay; Y=Ph 1; Fp 2; Tol 3; An- p­ 4; An- o­ 5; Tp 6; Mes 7; Tip 8) have been synthesised and their solid-state structures determined by X-ray crystallography. Molecular conformations were classified as a function of the two C9-C-Te-C(Y) dihedral angles ( θ); in the solid all members adopt AB or CC t configurations, with larger Te(aryl) moieties exclusively imposing the CC t variant. Exceptionally large J(125Te,125Te) spin-spin coupling constants between 3289-3848 Hz were obtained for compounds substituted by bulky Te(aryl) groups, implying these species are locked in a CC t-type conformation. In contrast, compounds incorporating smaller Te(aryl) moieties are predicted to be rather dynamic in solution and afford much smaller J values (2050-2676 Hz), characteristic of greater populations of AB conformers with lower couplings. This conformational dependence of through-space coupling is supported by DFT calculations. [ABSTRACT FROM AUTHOR]

Hybrid organic-inorganic materials of the type (diamine)MeSO4 (Me = Cd, Zn) [diamine = p-xylylenediamine (PXDA) or m-xylylenediamine (MXDA)] have not been described in the literature to date. Four compounds of this type, namely, (MXDA)ZnSO4 ( 1), (MXDA)CdSO4 ( 2), (PXDA)ZnSO4 ( 3), and (PXDA)CdSO4 ( 4), were synthesized by solvothermal methods. Since all compounds crystallized as very fine powders, crystal structure studies were performed using powder diffraction methods. All compounds crystallize in the orthorhombic crystal system and the cell parameters are: a = 9.8004(4) Å, b = 10.7829(3) Å, c = 4.88473(19) Å for 1; 9.8824(10), 11.0907(7), 4.9663(5) Å for 2; 9.8496(3), 21.2419(5), 4.89556(17) Å for 3; and 10.1136(4), 21.6625(3), 4.9562(2) Å for 4. The compounds with MXDA as a linker, crystallize in the space group P21 ma, those with PXDA in Pnma. These hybrid materials are built of inorganic monolayers [-Me-(SO4)-] joined by organic linkers created by diamines (PXDA or MXDA). Me metal ions and SO42- anions form layers with a honeycomb structure. In addition to crystal structure, chemical analyses and SEM investigations were performed. Thermal stability of the compounds was also investigated using TG-DSC methods and XRD as a function of temperature. [ABSTRACT FROM AUTHOR]

Calcium silicate, chemical environment, dielectric spectroscopy, nanoconfined water, nanominerals, supercritical fluids Keywords: calcium silicate; chemical environment; dielectric spectroscopy; nanoconfined water; nanominerals; supercritical fluids EN calcium silicate chemical environment dielectric spectroscopy nanoconfined water nanominerals supercritical fluids 11234 11234 1 08/07/21 20210805 NES 210805 B The ultra-fast synthesis of calcium silicate hydrates b was performed in supercritical water that acts as a solvent for mimicking the natural conditions at high pressure and high temperature of the geological process. [Extracted from the article]

Spin – spin coupling constants (SSCCs) provide valuable information about the environment surrounding coupled atomic nuclei within a molecule and are becoming an increasingly important tool for analysing structures. In their Full Paper on page 3613 ff., J. D. Woollins et al. use X ‐ ray crystallography, NMR spectroscopy and DFT calculations to investigate the conformational dependence of through ‐ space J(125Te,125Te) spin – spin coupling in three related series of peri ‐ substituted bis(tellurides). [ABSTRACT FROM AUTHOR]