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

Hexacoordinate germanate metal–organic frameworks for the detection of Pb²⁺ ions in aqueous solution

Hexacoordinate silicate and germanate linkers supporting high negative charges have been prepared and applied as building blocks for anionic MOF frameworks with lanthanide metal-based nodes. The SiO6/GeO6 centred linkers [Et3NH]2[H3L-Si/Ge] [H3L-Si/Ge = tris(3,4-diolato-benzoic acid) silicate/germanate] were initially prepared and characterised, with the germanate ligand demonstrating excellent water stability. A series of rare earth MOFs (IMP-33-Sc and IMP-34-Ln, Ln = Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were then synthesised under hydrothermal conditions using H3L-Ge. Both IMP-33-Sc and IMP-34-Ln exhibit (3,6)-connected networks with the same flu-3,6-C2/c topology, however, whereas IMP-33-Sc contains trimetallic nodes, IMP-34-Ln nodes are bimetallic, thus leading to a higher anionic network charge of 4− in IMP-34-Ln (vs. 1− in IMP-33-Sc). The terbium based MOF IMP-34-Tb exhibits characteristic luminescent properties and is shown to be selectively quenched by Pb2+ ions in aqueous solutions through a dynamic quenching process. A strong linear relationship between the fluorescence intensity and Pb2+ concentration in the range of 0.01–4 mM makes it a promising sensor for aqueous Pb2+ ions

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

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