Structures of tetrasilylmethane derivatives (XMe2Si)2C(SiMe3)2 (X = H, Cl, Br) in the gas phase, and their dynamic structures in solution

The structures of the molecules (XMe2Si)2C(SiMe3)2, where X = H, Cl, Br, have been determined by gas electron diffraction (GED) using the SARACEN method of restraints, with all analogues existing in the gas phase as mixtures of C1- and C2-symmetric conformers. Variable temperature 1H and 29Si solution-phase NMR studies, as well as 13C NMR and 1H/29Si NMR shift correlation and 1H NMR saturation transfer experiments for the chlorine and bromine analogues, are reported. At low temperatures in solution there appear to be two C1 conformers and two C2 conformers, agreeing with the isolated-molecule calculations used to guide the electron diffraction refinements. For (HMe2Si)2C(SiMe3)2 the calculations indicated six conformers close in energy, and these were modeled in the GED refinement

The Distress Thermometer and Its Validity: A First Psychometric Study in Indonesian Women with Breast Cancer.

Purpose: This study aims to translate the Distress Thermometer (DT) into Indonesian, test its validity in Indonesian women with breast cancer and determine norm scores of the Indonesian DT for clinically relevant distress. Methods: First, the original version of the DT was translated using a forward and backward translation procedure according to the guidelines. Next, a group of 120 breast cancer patients who were treated at the Outpatient Surgical Oncology Clinic in Hasan Sadikin Hospital in Indonesia completed a standard socio-demographic form, the DT and the Problem List, the Hospital Anxiety and Depression Scale (HADS) and the WHO Quality of Life (WHOQOL-BREF). Results: Receiver operating characteristic (ROC) curve analyses identified an area under the curve = 0.81 when compared to the HADS cutoff score of 15. A cutoff score of 5 on the DT had the best sensitivity (0.81) and specificity (0.64). Patients who scored above this cutoff reported more problems in the practical, family, emotional, spiritual/religious and physical domains (30 out of 36 problems, p-value<0.05) than patients below the cutoff score. Patients at advanced stages of cancer experienced more emotional and physical problems. Patient's distress level was negatively correlated with overall quality of life, general health and all quality of life domains. Conclusions: The DT was found to be a valid tool for screening distress in Indonesian breas

Studies on the structural diversity of MOFs containing octahedral siloxane-backboned connectors

Four metal–organic frameworks containing hexatopic connectors have been prepared and structurally characterised: [Cd3(L)(DMA)2(H2O)2] (IMP-28), [Ce2(L)(DMF)2(H2O)2] (IMP-29), [Y2(L)(DMF)2(H2O)2] (IMP-30), and [Zn2(L-H2)(4,4′-bipy)2] (IMP-31). All the MOFs have been constructed using the hybrid inorganic–organic siloxane linker hexakis(4-carboxyphenyl)disiloxane (L-H6). In each case, discrete metal-based nodes are cross-linked by the octahedrally disposed connector to afford 3D polymeric structures. The underlying nets in these MOFs have been evaluated through deconstruction of their crystal structures and subsequent topological analysis. Examples of MOFs built from hexatopic linkers, and especially those with octahedral predispositions such as in L, remain scarce and the topologies ascribed to some of these MOFs are unique.</p

Trisiloxane-centred metal-organic frameworks and hydrogen bonded assemblies

A hexacarboxylic acid with a trisiloxane backbone (L-H6) has been prepared and applied in MOF construction. L-H6 itself crystallizes as an unusual 2D hydrogen-bonded network. Reaction of L-H6 with Mn(ii) gave IMP-20 and with Zn(ii) gave IMP-21: both are 3D MOFs incorporating Si-O-Si-O-Si linkages.</p

First example of solid-state luminescent borasiloxane-based chiral helices assembled through N-B bonds

The reaction between differently substituted borasiloxanes and 2,5-bis(3-pyridylethynyl)thiophene provided the first example of luminescent borasiloxane-based chiral helices held together by N-B bonds. The starting building blocks and the helices were fully characterized, and the nature of the N-B bond rationalized by means of theoretical calculations

Metal–Organic Frameworks Constructed from Group 1 Metals (Li, Na) and Silicon-Centered Linkers

A series of “light metal” metal–organic frameworks containing secondary building units (SBUs) based on Li⁺ and Na⁺ cations have been prepared using the silicon-centered linkers Me_<i>x</i>Si­(<i>p</i>-C₆H₄CO₂H)_4‑<i>x</i> (<i>x</i> = 2, 1, 0). The unipositive charge, small size, and oxophilic nature of the metal cations give rise to some unusual and unique SBUs, including a three-dimensional nodal structure built from sodium and oxygen ions when using the triacid linker (<i>x</i> = 1). The same linker with Li⁺ cations generated a chiral, helical SBU, formed from achiral starting materials. One-dimensional rod SBUs are observed for the diacid (<i>x</i> = 2) and tetra-acid (<i>x</i> = 0) linkers with both Li⁺ and Na⁺ cations, where the larger size of Na⁺ compared to Li⁺ leads to subtle differences in the constitution of the metal nodes

Incorporation of group 14 elements into siloxane-bridged paracyclophanes cyclo-[p,p´-Me2SiC6H4EMe2C6H4SiMe2O]2 (E = C, Si, Ge, Sn)§

The bis(arylene silanes) p,p\u27-HMe2SiC6H4EMe2C6H4SiMe2H (E = C (10), Si (11), Ge (12), Sn(13)) were prepared by the in situ Grignard reaction of p,p\u27-BrC6H4CMe2C6H4Br, Mg turnings, and HSiMe2Cl (for 10) and the Grignard reaction using p-HMe2SiC6H4Br, Mg turnings, and Me2ECl2 (E = Si for 11, Ge for 12, Sn for 13). The oxidation of 10-13 using Pearlman\u27s catalyst, Pd(OH)2/C, in aqueous THF provided the bis(arylene silanols) p,p\u27-HOMe2SiC6H4EMe2C6H4SiMe2OH (E = C (14), Si (15), Ge (16), Sn(17)). The HCl-catalyzed condensation of 14-17 in highly diluted solutions of acetone/water afforded the siloxane-bridged paracyclophanes cyclo-[p,p\u27-Me2SiC6H4EMe2C6H4SiMe2O]2 (6-9) that incorporate the group 14 elements E = C, Si, Ge, and Sn. Compounds 6-17 were investigated by multinuclear solution and solid-state NMR spectroscopy and 6 and 9 also by X-ray crystallography.<br /