Gas and Liquid Phase Diffusivities of Isomeric Metal Complexes Derived from Multifold Ring-Closing Metatheses: Ion Mobility Mass Spectrometry Trumps DOSY NMR

Abstract

Isomeric octahedral osmium and rhenium complexes of formulas M(CO) y (X) z (P((CH 2 ) n ) 3 P) and M(CO) y (X) z -

Syntheses, Reactivity, Structures, and Dynamic Properties of Gyroscope-like Iron Carbonyl Complexes Based on Dibridgehead Diarsine Cages

“…Scheme establishes that trigonal bipyramidal gyroscope-like iron tricarbonyl complexes with dibridgehead diarsine stators ( 4a – c ) can be accessed similarly to the diphosphine analogues reported earlier . The overall yields are comparable (41–59% vs 50–64%) and higher than those obtained via ring-closing metatheses of related square planar and octahedral complexes. − , This has been attributed to a conformational preference for staggered alkyl/CO/alkyl As–Fe–As or P–Fe–P substituents in precursors of the type 2a – c . This enforces a syn relationship between the (CH 2 ) m CHCH 2 groups that must react with each other, as can easily be visualized with the arsenic–carbon bonds in the crystal structure of the model bis­(arsine) complex 8 (right view, Figure ).…”

“…Our research group has undertaken extensive investigations of dibridgehead diphosphine complexes of the type I (Scheme ). ,− These are accessed in surprisingly high yields via 3-fold intramolecular ring-closing metatheses of bis­(phosphine) complexes of the formula trans -ML y (P­((CH 2 ) m CHCH 2 ) 3 ) 2 . Both the lengths of the methylene chains that connect the two phosphorus atoms and the sizes of the ancillary ligands (L y ) are easily varied.…”

General Approach to Direct Measurement of the Hydration State of Coordination Complexes in the Gas Phase: Variable Temperature Mass Spectrometry

“…Such structural transformations upon introduction to the gas phase can be reliably diagnosed using ion mobility mass spectrometry to determine the collision cross-section of the gas-phase complex as compared to that predicted by molecular dynamics simulations. 53 This additional information, which can be obtained using increasingly common commercial instrumentation, will substantially improve the predictive capability of this technique. However, for first row transition metal ions in which these transformations are likely, well-established NMR methods already exist, and thus the benefit of using VT-MS is minimal.…”

Partially Shielded Fe(CO)3 Rotors: Syntheses, Structures, and Dynamic Properties of Complexes with Doubly trans Spanning Diphosphines, trans-Fe(CO)3(PhP((CH2)n)2PPh)

“…The intersection of alkene metathesis and inorganic or organometallic synthesis has proved to be a rich area, allowing targeted approaches to a variety of complex metal-containing molecules. , We evolved initial interests in metallomacrocycle and metallamacrocycle syntheses ( I and II in Scheme ) , into a program involving gyroscope-like complexes of the general type IIIa . − These are distinguished by three methylene chains that span two trans -phosphorus donor atoms and are assembled by alkene metathesis/hydrogenation sequences. Some of the most interesting and intensively studied species have trigonal planar iron carbonyl cores or “rotators” (Fe­(CO) 3 , Fe­(CO) 2 (NO) + , Fe­(CO)­(NO)­(X)) within the di bridgehead di phosphine “stators”.…”