Solid-state (35)Cl NMR (SSNMR) spectroscopy is shown to be a useful probe of structure and polymorphism in HCl pharmaceuticals, which constitute ca. 50% of known pharmaceutical salts. Chlorine NMR spectra, single-crystal and powder X-ray diffraction data, and complementary ab initio calculations are presented for a series of HCl local anesthetic (LA) pharmaceuticals and some of their polymorphs. (35)Cl MAS SSNMR spectra acquired at 21.1 T and spectra of stationary samples at 9.4 and 21.1 T allow for extraction of chlorine electric field gradient (EFG) and chemical shift (CS) parameters. The sensitivity of the (35)Cl EFG and CS tensors to subtle changes in the chlorine environments is reflected in the (35)Cl SSNMR powder patterns. The (35)Cl SSNMR spectra are shown to serve as a rapid fingerprint for identifying and distinguishing polymorphs, as well as a useful tool for structural interpretation. First principles calculations of (35)Cl EFG and CS tensor parameters are in good agreement with the experimental values. The sensitivity of the chlorine NMR interaction tensor parameters to the chlorine chemical environment and the potential for modeling these sites with ab initio calculations hold much promise for application to polymorph screening for a wide variety of HCl pharmaceuticals.

Fit for a king: Cationic complexes of Ge(II) can be prepared by using crown ethers to stabilize and protect the germanium center. Three different crown ethers were employed: [12]crown-4 (see structure, Ge teal, O red, C gray), [15]crown-5, and [18]crown-6. The structures of the cationic complexes depend on the cavity size of the crown ether and on the substituent on germanium.

An in situ redox method is employed to prepare N-heterocyclic bromophosphines in good yield and purity. Such bromophosphines may be treated with a variety of bromide-abstracting reagents to produce the corresponding N-heterocyclic phosphenium salts in excellent yield.Salts containing phosphenium cations have played an important role in the history and development of modern maingroup chemistry. In the most general definition, a phosphenium cation ( 1) is a cation that contains a dicoordinate phosphorus center bearing a total of six valence electrons and is the isovalent analogue of a carbene (2). 1,2 While numerous types of phosphenium cations have been prepared and studied, the most important class of phosphenium compounds is the relatively stable species in which the dicoordinate phosphorus center is supported by two adjacent amido substituents. Although such compounds are analogous to the now-ubiquitous N-heterocyclic carbenes (NHCs, 3) 3,4 and may be labeled N-heterocyclic phosphenium cations (NHPs, 4), it is worth noting that well-characterized NHPs were reported more than 35 years ago 5,6 and thus predate the first report of a stable NHC considerably. In fact, the structural characterization of a salt containing a 1,3,2-diazaphospholenium cation, an unsaturated NHP directly analogous to the most common type of "Arduengo" NHC, 7 was reported as early as 1990. 8

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