Sample end effects.

In high-resolution NMR spectroscopy, the variation of the magnetic field inside the sample has a measurable impact on lineshape. We present a model to calculate the moments of the internal field, as they relate to the current that should be set in the compensation coils to level the magnetic perturbations originating from the sample. We apply this model to common sample geometries, and discuss the practical implications for sample-limited applications.

Recent advances in the synthesis of natural multifunctionalized decalins.

This review highlights recent innovative synthetic strategies developed for the stereoselective construction of natural complex decalin systems. It offers an insight into various synthetic targets and approaches and provides information for developments within the area of natural products as well as synthetic methodology.

X-ray crystal structure, Raman spectroscopy, and Ab initio density functional theory calculations on 1,1,3,3-tetramethylguanidinium bromide.

The salt 1,1,3,3-tetramethylguanidinium bromide, [((CH(3))(2)N)(2)C═NH(2)](+)Br(-) or [tmgH]Br, was found to melt at 135(5) °C, forming what may be referred to as a moderate temperature ionic liquid. The chemistry was studied and compared with the corresponding chloride compound. We present X-ray diffraction and Raman evidence to show that also the bromide salt contains dimeric ion pair "molecules" in the crystalline state and probably also in the liquid state.

Crystal structure, vibrational spectroscopy and ab initio density functional theory calculations on the ionic liquid forming 1,1,3,3-tetramethylguanidinium bis{(trifluoromethyl)sulfonyl}amide.

The salt 1,1,3,3-tetramethylguanidinium bis{(trifluoromethyl)sulfonyl}amide, [((CH(3))(2)N)(2)C=NH(2)](+)[N(SO(2)CF(3))(2)](-) or [tmgH][NTf(2)], easily forms an ionic liquid with high SO(2) absorbing capacity. The crystal structure of the salt was determined at 120(2) K by X-ray diffraction. The structure was found to be monoclinic, space group P2(1)/n with a = 11.