Automation in solid state NMR.

Automation in solid state NMR (ssNMR) requires appropriate hardware, from rotor loading mechanisms over highly stable rf-transmitters and probe circuitry to automatic tuning and matching capabilities including automatic magic angle adjustment for ssNMR probes. While these hardware capabilities are highly desirable and are, to various degrees, provided by manufacturers, we focus herein on automating experiment setup using radio frequency (rf) fields, which are key parameters in solid state NMR experiments. Specifically, these include spinlock fields during cross polarization (CP), or rf-fields for homo- or heteronuclear spin recoupling or decoupling.

Host-Guest Interactions between Calixarenes and Cp(2)NbCl(2).

The possible inclusion complexes of Cp(2)NbCl(2) into calixarenes hosts have been investigated. The existence of a true inclusion complex in the solid state was confirmed by a combination of NMR, ab-initio calculations, thermogravimetric analysis, FTIR, Raman and PXRD. Ab-initio calculations, (1)H NMR solution and solid state (13)C CP MAS NMR results demonstrated that p-sulfonic calix[6]arene does form an inclusion complex with Cp(2)NbCl(2).

Intermolecular protein-RNA interactions revealed by 2D 31P-15N magic angle spinning solid-state NMR spectroscopy.

The structural investigation of large RNP complexes by X-ray crystallography can be a difficult task due to the flexibility of the RNA and of the protein-RNA interfaces, which may hinder crystallization. In these cases, NMR spectroscopy is an attractive alternative to crystallography, although the large size of typical RNP complexes may limit the applicability of solution NMR. Solid-state NMR spectroscopy, however, is not subject to any intrinsic limitations with respect to the size of the object under investigation, with restrictions imposed solely by the sensitivity of the instrumentation.

Non-polar halogenated natural products bioaccumulated in marine samples. I. 2,3,3',4,4',5,5'-Heptachloro-1'-methyl-1,2'-bipyrrole (Q1).

This presentation adds new spectroscopic and analytical data on the natural product Q1 that was recently identified by synthesis as 2,3,3('),4,4('),5,5(')-heptachloro-1(')-methyl-1,2(')-bipyrrole. Solid state magic angle spinning 13C NMR data of Q1 is presented as an option for structural proof. Furthermore, the UV spectrum of neat Q1 (absorption maximum at 223 nm) was recorded and, with NMR spectroscopic data, confirmed a twisted bipyrrole ring system.