Seven bipyridine adducts of molybdenum imido alkylidene bispyrrolide complexes of the type Mo(NR)(CHCMe(2)R')(Pyr)(2)(bipy) (1a-1g; R = 2,6-i-Pr(2)C(6)H(3) (Ar), adamantyl (Ad), 2,6-Me(2)C(6)H(3) (Ar'), 2-i-PrC(6)H(4) (Ar(iPr)), 2-ClC(6)H(4) (Ar(Cl)), 2-t-BuC(6)H(4) (Ar(t) (Bu)), and 2-MesitylC(6)H(4) (Ar(M)), respectively; R' = Me, Ph) have been prepared using three different methods. Up to three isomers of the adducts are observed that are proposed to be the trans and two possible cis pyrrolide isomers of syn alkylidenes. Sonication of a mixture containing 1a-1g, HMTOH (2,6-dimesitylphenol), and ZnCl(2)(dioxane) led to the formation of MAP species of the type Mo(NR)(CHCMe(2)R')(Pyr)(OHMT) (3a-3g). DCMNBD (2,3-dicarbomethoxynorbornadiene) is polymerized employing 3a-3g as initiators to yield >98% cis,syndiotactic poly(DCMNBD). Attempts to prepare bipy adducts of bisdimethylpyrrolide complexes led to formation of imido alkylidyne complexes of the type Mo(NR)(CCMe(2)R')(Me(2)Pyr)(bipy) (Me(2)Pyr = 2,5-dimethylpyrrolide; 4a - 4g) through a ligand-induced migration of an alkylidene α proton to a dimethylpyrrolide ligand. X-ray structures of Mo(NAr)(CHCMe(2)Ph)(Pyr)(2)(bipy) (1a), Mo(NAr(iPr))(CHCMe(2)Ph)(Pyr)(OHMT) (3d), Mo(NAr)(CCMe(2)Ph)(Me(2)Pyr)(bipy) (4a), and Mo(NAr(T))(CCMe(3))(Me(2)Pyr)(bipy) (Ar(T) = 2-(2,4,6-i-Pr(3)C(6)H(2))C(6)H(4); 4g) showed structures with the normal bond lengths and angles.
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http://dx.doi.org/10.1021/om300353e | DOI Listing |
Inorg Chem
January 2025
Testing and Analysis Center, Hebei Normal University, Shijiazhuang 050024, China.
The bipyridyl tantalum complex (2,6-PrCHO)Ta(bipy) () is synthesized by the reaction of (2,6-PrCHO)TaCl () and 2,2'-bipyridine in the presence of excess potassium graphite (KC). Complex coordinates readily with pyridine and 4-(dimethylamino)pyridine (dmap) to form Lewis base adducts (2,6-PrCHO)Ta(bipy)(L) (L = py (), dmap ()), and it exhibits rich redox reactivity toward small molecules: (a) single electron transfer (SET) occurs upon exposure of to phenyl sulfide or selenide dimer, giving the open-shell, bipy-centered radical complexes (2,6-PrCHO)Ta(bipy)(PhE) (E = S (), Se ()). (b) Regioselective C-C σ-bond formation via radical coupling is observed in the SET reaction of and aldehydes, ketones, or imines to furnish insertion products -, namely, sterically more crowded benzophenone, acetophenone, 2,6-dichlorobenzaldehyde, and benzophenone imine couple with C6 or C6' of bipy in , respectively, whereas sterically less hindered benzaldehyde, cyclohexanone, and benzylideneaniline couple with C2 or C2' of bipy, respectively.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China.
Easily obtainable and efficient chiral -symmetric bipyridine-,'-dioxide ligands with Ni(OTf) were developed for application in catalyzing [3 + 2] cycloaddition reactions to synthesize optically active fused pyrazolidines or pyrazoline derivatives featuring three contiguous stereogenic centers by employing azomethine imines and α,β-unsaturated 2-acyl imidazoles, affording the corresponding adducts with the opposite configuration compared to previous synthetic products in 80-98% yields with 28-99% ee and >20:1 dr. In addition, subsequent amplification experiments and derivative transformations of the product further demonstrated the efficient catalytic performance of the catalyst Ni(II)-bipyridine-,'-dioxide complexes and the practicality of this synthesis methodology.
View Article and Find Full Text PDFChem Sci
December 2024
Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt Max-von-Laue-Straße 7 D-60438 Frankfurt (Main) Germany
Phys Chem Chem Phys
October 2024
Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, 1090 Vienna, Austria.
Ruthenium(II) polypyridyl complexes are attractive binders to DNA. Modifying the hydrophobicity, shape, or size of the ancillary ligands around the central ruthenium atom can induce changes in the binding mode to the DNA double helix. In this paper, we investigate the binding modes of [Ru(2,2'-bipyridine) (5-{4-[(pyren-1-yl)methyl]-1-1,2,3-triazol-4-yl}-1,10-phenanthroline)] (RuPy for short), a metal complex featuring a flexible pyrene moiety known for its intercalative properties.
View Article and Find Full Text PDFJ Am Chem Soc
September 2024
Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973-5000, United States.
We report a series of isomeric, dicationic Re(bpy)(CO)I complexes with bpy (2,2'-bipyridine) modified by two phenyl-CH-(NMe) pendants with cations located at variable distances from the active site for electrocatalytic CO reduction in CHCN/2.8 M HO. The position of the cationic groups dramatically increases the rate of catalysis by ∼800-fold, from 1.
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