More Like this

1. Primary and Secondary Coordination Sphere Lewis Acid Interactions in β-Phosphinoethylborane-ligated Rhodium and Iridium Complexes

   https://doi.org/10.1039/d5nj01429h  

   Nichols, Brian R; Petersen, Jeffrey L; Dolinar, Brian; Popp, Brian V (July 2025, New Journal of Chemistry)

   Flexible ambiphilic ligand scaffolds have garnered attention in catalysis due to their ability to adopt multiple binding orientations. Recently, several platinum group metal complexes featuring the flexible, ambiphilic b-phosphinoethylborane ligand were reported in the literature; however, the impact of primary coordination sphere ligands and solvent on the properties of the Lewis acidic borane moiety remain underexplored. Rhodium and iridium complexes ligated by 9-borabicyclo[3.3.1]nonanyl-based b- diphenylphosphinoethylborane were studied using a combination of crystallography and 11B NMR spectroscopy. The studies revealed that both the primary coordination sphere and solvent had an impact on the formation of Lewis acid–base adducts. Specifically, inner-sphere Lewis pair formation was dependent on the nature of the X-type ligand bound to the metal center. Similar dependencies were identified with solvents in which Lewis acid interaction was found to correlate with solvent donor number. 

   more » « less
2. Late-stage ligand functionalization via the Staudinger reaction using phosphine-appended 2,2′-bipyridine

   https://doi.org/10.1039/D1CC01407B  

   Taher, Deeb; Wilson, Jessica R.; Ritch, Grayson; Zeller, Matthias; Szymczak, Nathaniel K. (June 2021, Chemical Communications)

   null (Ed.)

   The ability of a phosphine-appended-2,2′-bipyridine ligand ((Ph 2 P) 2 bpy) to serve as a platform for late-stage ligand modifications was evaluated using tetrahedral (Ph 2 P) 2 bpyFeCl 2 . We employed a post-metalation Staudinger reaction to install a series of functionalized arenes, including those containing Brønsted and Lewis acidic groups. This reaction sequence represents a versatile strategy to both tune the ligand donor properties as well as directly incorporate appended functionality. 

   more » « less
3. Substrate Specific Metal–Ligand Cooperative Binding: Considerations for Weak Intramolecular Lewis Acid/Base Pairs

   https://doi.org/10.1021/acs.inorgchem.1c01382  

   Kiernicki, John J.; Norwine, Emily E.; Zeller, Matthias; Szymczak, Nathaniel K. (January 2021, Inorganic Chemistry)

   null (Ed.)

   Metal–ligand cooperative binding modes were interrogated in a series of zinc bis(thiophenoxide) complexes. A weak B–S binding interaction is observed in solution between the weakly Lewis basic thiophenoxide ligands and an appended trialkylborane. The energy of this binding event is dependent upon the strength of the Lewis acid and its proximity to the zinc thiophenoxide. 

   more » « less
4. Synthesis and reactivity of nitridorhenium complexes incorporating the mercaptoethylsulfide (SSS) ligand

   https://doi.org/10.1039/d0dt00631a  

   Lambic, Nikola S.; Sommer, Roger D.; Ison, Elon A. (May 2020, Dalton Transactions)

   A method for the preparation of nitridorhenium( v ) complexes of the form (SSS)Re(N)(L) (where SSS = 2-mercaptoethylsulfide and L = PPh 3 and t -BuNC) has been described. These complexes react with Lewis acids allowing for the isolation of adducts. The lack of a significant steric profile on the SSS ligand combined with enhanced nucleophilicity of the nitrido group does not allow for the effective formation of frustrated Lewis pairs with these complexes and as a result these species are poor catalysts for the hydrogenation of unactivated olefins. 

   more » « less
5. Structural Evidence for Pnictogen-Centered Lewis Acidity in Cationic Platinum-Stibine Complexes Featuring Pendent Amino or Ammonium Groups

   https://doi.org/10.3390/molecules26071985  

   Rodrigues, Roberta R.; Gabbaï, François P. (April 2021, Molecules)

   null (Ed.)

   As part of our continuing interest in the chemistry of cationic antimony Lewis acids as ligands for late transition metals, we have now investigated the synthesis of platinum complexes featuring a triarylstibine ligand substituted by an o-[(dimethylamino)methyl]phenyl group referred to as ArN. More specifically, we describe the synthesis of the amino stibine ligand Ph2SbArN (L) and its platinum dichloride complex [LPtCl]Cl which exists as a chloride salt and which shows weak coordination of the amino group to the antimony center. We also report the conversion of [LPtCl]Cl into a tricationic complex [LHPt(SMe2)]3+ which has been isolated as a tris-triflate salt after reaction of [LPtCl]Cl with SMe2, HOTf and AgOTf. Finally, we show that [LHPt(SMe2)][OTf]3 acts as a catalyst for the cyclization of 2-allyl-2-(2-propynyl)malonate. 

   more » « less