Gold(III), Mercury(II), and Palladium(II) Complexes of a Series of Isomeric Bis(mono- and dialkoxyphenyl)pyridines: Introduction of Gold through Transmetalation and Catalysis.

A series of isomeric bis-2,6-(monoalkoxyphenyl)pyridine and bis-2,6-(dialkoxyphenyl)pyridine ligands were synthesized and characterized. In order to prepare their chlorogold(III) complexes, intermediate chloromercury(II) complexes were first prepared, but unlike observations from previous studies where they were obtained impure and at best in moderate yield, here pure complexes were synthesized, many in rather high yields. Depending on the substitution pattern of the alkoxy chains on the ligands, mono- and/or dimercurated complexes were obtained, characterized by 1H, 13C{1H}, and 199Hg NMR spectroscopy as well as, in several cases, by X-ray crystallography. Factors that may explain this unusual reactivity are discussed. In most cases, transmetalation to the related chlorogold(III) complex proceeded smoothly, although lower yields were obtained when starting from doubly mercurated precursors. Prompted by the propensity of these ligands to mercurate, attempts were made to effect direct auration, but none was successful. However, dimeric, orthometalated complexes of palladium(II) could be prepared and were also amenable to transmetalation to the chlorogold(III) complex, providing for a mercury-free synthesis.

Enhancing the Air Stability of Dimolybdenum Paddlewheel Complexes: Redox Tuning through Fluorine Substituents.

The optical and electrochemical properties of quadruply bonded dimolybdenum paddlewheel complexes (Mo2PWCs) make them ideal candidates for incorporation into functional materials or devices, but one of the greatest bottlenecks for this is their poor stability toward atmospheric oxygen. By tuning the potential at which the Mo2 core is oxidized, it was possible to increase the tolerance of Mo2PWCs to air. A series of homoleptic Mo2PWCs bearing fluorinated formamidinate ligands have been synthesized and their electrochemical properties studied. The oxidation potential of the complexes was tuned in a predictable fashion by controlling the positions of the fluorine substituents on the ligands, as guided by a Hammett relationship. Studies into the air stability of the resulting complexes by multinuclear NMR spectroscopy show an increased tolerance to atmospheric oxygen with increasingly electron-withdrawing ligands. The heteroleptic complex Mo2(DFArF)3(OAc) [where DFArF = 3,5-(difluorophenyl)formamidinate] shows remarkable tolerance to oxygen in the solid state and in chloroform solutions. Through the employment of easily accessible ligands, the stability of the Mo2 core toward oxygen has been enhanced, thereby making Mo2PWCs with electron-withdrawing ligands more attractive candidates for the development of functional materials.

Hydrogen/Halogen Exchange of Phosphines for the Rapid Formation of Cyclopolyphosphines.

The hydrogen/halogen exchange of phosphines has been exploited to establish a truly useable substrate scope and straightforward methodology for the formation of cyclopolyphosphines. Starting from a single dichlorophosphine, a sacrificial proton "donor phosphine" makes the rapid, mild synthesis of cyclopolyphosphines possible: reactions are complete within 10 min at room temperature. Novel (aryl)cyclopentaphosphines (ArP)5 have been formed in good conversion, with the crystal structures presented. The use of catalytic quantities of iron(III) acetylacetonate provides significant improvements in conversion in the context of diphosphine (Ar2P)2 and alkyl-substituted cyclotetra- or cyclopentaphosphine ((AlkylP)n, where n = 4 or 5) formation. Both iron-free and iron-mediated reactions show high levels of selectivity for one specific ring size. Finally, investigations into the reactivity of Fe(acac)3 suggest that the iron species is acting as a sink for the hydrochloric acid byproduct of the reaction.

Correction: On the mercuration, palladation, transmetalation and direct auration of a C

Correction for 'On the mercuration, palladation, transmetalation and direct auration of a C^N^C pincer ligand' by Alice Jane McEllin et al., Dalton Trans., 2023, 52, 872-876, https://doi.org/10.1039/d2dt04114f.

On the mercuration, palladation, transmetalation and direct auration of a C

The C^N^C ligand 2,6-bis(2,3-dialkoxyphenyl)pyridine forms dimercury and orthopalladated complexes, both of which may be transmetallated to gold(III) complexes; the gold complexes may also be formed directly in a Rh(III)-catalysed process, hence it is possible to circumvent the use of organomercury intermediates in the synthesis of this important class of compound.

Spinal Manipulation and Electrical Dry Needling in Patients With Subacromial Pain Syndrome: A Multicenter Randomized Clinical Trial.

OBJECTIVES: To compare the effects of spinal thrust manipulation and electrical dry needling (TMEDN group) to those of nonthrust peripheral joint/soft tissue mobilization, exercise, and interferential current (NTMEX group) on pain and disability in patients with subacromial pain syndrome (SAPS). DESIGN: Randomized, single-blinded, multicenter parallel-group trial. METHODS: Patients with SAPS were randomized into the TMEDN group (n = 73) or the NTMEX group (n = 72). Primary outcomes included the Shoulder Pain and Disability Index and the numeric pain-rating scale. Secondary outcomes included the global rating of change scale (GROC) and medication intake. The treatment period was 6 weeks, with follow-ups at 2 weeks, 4 weeks, and 3 months. RESULTS: At 3 months, the TMEDN group experienced greater reductions in shoulder pain and disability (P<.001) compared to the NTMEX group. Effect sizes were large in favor of the TMEDN group. At 3 months, a greater proportion of patients within the TMEDN group achieved a successful outcome (GROC score of 5 or greater) and stopped taking medication (P<.001). CONCLUSION: Cervicothoracic and upper-rib thrust manipulation combined with electrical dry needling resulted in greater reductions in pain, disability, and medication intake than nonthrust peripheral joint/soft tissue mobilization, exercise, and interferential current in patients with SAPS. The effects were maintained at 3 months. J Orthop Sports Phys Ther 2021;51(2):72-81. Epub 28 Aug 2020. doi:10.2519/jospt.2021.9785.