One of the paradigms of chemistry predicts that the shorter the bond of a given type is always the stronger bond. Although this qualitatively holds for many compounds, there exists no general proof that this is always correct. Here, we discuss molecules, for which longer bonds lead to stronger rather than weaker bonds. This is possible by introducing the local mode stretching force constants as...

Motivated by solid-state studies on the cleavage force in Si, and the consequent stretching of chemical bonds, we here study bond stretching in the, as yet unsynthesized, free space molecule Si6H6. We address the question as to whether substantial bond stretching (but constrained to uniform scaling on all bonds) can result in a transition from ring current behaviour, characteristic say of benze...

Matrix isolation infrared spectra of nitrosyl halide (XNO) complexes with HX and X2 (X = Cl, Br) are presented. The r elative frequency shifts of the HX mode are modest (ClNO · H-Cl, !':..:v/v = = 0.045; BrNO·H-Br, Av/v = ·-0.026), indicating weak hydrogen bonds 1-3 kcal/mo!. These shifts are accompanied by significant shifts to higher frequencies in the XN-0 stretching mode (CIN-O · HCl, Av/v ...

Front Cover: In article number 2100061 by Wei Zhang and co-workers, a high-strength PVA-TA hydrogel shows efficient self-healing performance. The strength is demonstrated through stretching the cube. intermediate fracture network of gradually healed reconstruction H bond between TA PVA polymer chains.

The Wingate Anaerobic Test (WAnT) has been used in many studies to determine anaerobic performance. However, there has been poor reporting of warm-up protocols and limited consistency between warm-up methods that have been used. With the WAnT being such a commonly-used test, consistency in warm-up methods is essential in order to compare results across studies. Therefore, this study was designe...

Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) angstroms. EXAFS spectra yield a mean Sc-O bond distance of 2.09(1) angstroms for solvated scandium(III) ions in dimethyl sulfoxide solution, consistent with six-coordination. Raman and infrared absorption spectra have been re...

4-mercaptobenzonitrile (MBN) in self-assembled monolayers (SAMs) on Au and Ag electrodes was studied by surface enhanced infrared absorption and Raman spectroscopy, to correlate the nitrile stretching frequency with the local electric field exploiting the vibrational Stark effect (VSE). Using MBN SAMs in different metal/SAM interfaces, we sorted out the main factors controlling the nitrile stre...

4-mercaptobenzonitrile (MBN) in self-assembled monolayers (SAMs) on Au and Ag electrodes was studied by surface enhanced infrared absorption and Raman spectroscopy, to correlate the nitrile stretching frequency with the local electric field exploiting the vibrational Stark effect (VSE). Using MBN SAMs in different metal/SAM interfaces, we sorted out the main factors controlling the nitrile stre...

Ab initio calculations have been carried out to investigate the structure and infrared spectrum of BrH:NH3, and to resolve the discrepancies found between its computed harmonic and experimental spectrum. MP2/6-31+G(d, p) and MP2/aug -cc-pVDZ potential surfaces have been constructed, and a model two-dimensional nuclear vibrational problem has been solved to obtain the fundamental dimer stretchi...

Two-dimensional infrared photon-echo measurements of the OH stretching vibration in liquid H2O are performed at various temperatures. Spectral diffusion and resonant energy transfer occur on a time scale much shorter than the average hydrogen bond lifetime of approximately 1 ps. Room temperature measurements show a loss of frequency and, thus, structural correlations on a 50-fs time scale. Weak...