A redetermination of the crystal structure of the title compound, C(6)H(16)N(2) (2+)·2Cl(-), was undertaken. All atomic coordinates including those of the H atoms were refined freely. The cation is located on a centre of symmetry. Important for the crystal structure are wavy hydrogen-bonded layers that are formed by ammonium groups and chloride anions, giving hydrogen-bonded rings.

In the title compound, C(12)H(12)O(5), mol-ecules are linked into anti-parallel hydrogen-bonded sheets through inversion dimers generated via two O-H⋯O hydrogen bonds. Using the R(2) (2)(8) motif as a building block, hydrogen-bonded chains of a C(2) (2)(8) superstructure are then generated.

A template-assisted method that enables the growth of covalently bonded three-dimensional carbon nanotubes (CNTs) originating from graphene at a large scale is demonstrated. Atomic force microscopy-based mechanical tests show that the covalently bonded CNT structure can effectively distribute external loading throughout the network to improve the mechanical strength of the material.

In the crystal structure of the title compound, C(8)H(12)N(+)·Cl(-), all H atoms bonded to the ammonium N atom are hydrogen bonded to the chloride ions, with N⋯Cl distances in the range 3.080 (2)-3.136 (2) Å, resulting in 16-membered macrocyclic rings involving four formula units of the title compound.

The objective of this study was to survey retention procedures used in orthodontic practices in The Netherlands. A questionnaire was sent to all 279 orthodontists working in The Netherlands. The questionnaire consisted of six parts, mainly containing multiple-choice questions. Information as to background data on the individual orthodontist, retention in general, frequency of different types of...

Pathologic and experimental evidence indicates that platelet activation and fibrin formation contribute to the pathogenesis of angina pectoris, coronary vasospasm and myocardial infarction. Detection of localized intravascular platelet activation and fibrin formation in vivo by selective blood sampling requires catheters that do not induce coagulation ex vivo. We studied the effect of heparin b...

A method for generating angular forces around sigma-bonded transition metal ions is generalized to treat pi-bonded configurations. The theoretical approach is based on an analysis of ligand-field and small-cluster Hamiltonians based on the moments of the electron state distribution. The functional forms that are obtained involve a modification of the usual expression of the binding energy as a ...

We investigated the dynamics of excited-state proton transfer (ESPT) of photo-amphiprotic 7-hydroxyquinoline (7HQ) in the presence of a hydrogen (H)-bond bridging diol in a polar aprotic medium. The formation of 1 : 1 H-bonded complexes of 7HQ with various diols of different alkane chain lengths was revealed using steady-state electronic spectroscopy. With femtosecond-resolved fluorescence spec...

A comprehensive investigation of the surfaces of copper through silicon vias Cu-TSVs and gold stud bumps is presented. These vias and stud bumps were bonded at room temperature using a nanobonding and interconnection equipment. The influence of heating on the bonded interface was also studied. In order to achieve an intimate contact between the Au-stud bumps and Cu-TSVs, the stud bumps were fla...

The measurement of the dimerization constants of hydrogen-bonded ruthenium complexes (12, 22, 32) linked by a self-complementary pair of 4-pyridylcarboxylic acid ligands in different redox states is reported. Using a combination of FTIR and UV/vis/NIR spectroscopies, the dimerization constants (KD) of the isovalent, neutral states, 12, 22, 32, were found to range from 75 to 130 M-1 (ΔG0 = -2.56...