skip to main content


Title: Synthesis and characterization of a ruthenium-containing copolymer for use as a photoredox catalyst

We present a [Ru(bpy)2(dmbpy)]2+- and pyrene-based photocatalytic PMMA that enables photoredox-energy transfer to achieve the C–H arylation of electron deficient aryl bromides.

 
more » « less
Award ID(s):
2046470
PAR ID:
10483402
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Royal Society of Chemistry
Date Published:
Journal Name:
Polymer Chemistry
Volume:
14
Issue:
39
ISSN:
1759-9954
Page Range / eLocation ID:
4560 to 4568
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Low‐temperature reaction of the tris(pyrazolyl)borate copper(II) hydroxide [iPr2TpCu]2(μ‐OH)2with triphenylsilane under a dinitrogen atmosphere gives the bridging dinitrogen complex [iPr2TpCu]2(μ‐1,2‐N2) (3). X‐ray crystallography reveals an only slightly activated N2ligand (N‐N: 1.111(6) Å) that bridges between two monovalentiPr2TpCu fragments. While DFT studies of mono‐ and dinuclear copper dinitrogen complexes suggest weak π‐backbonding between the d10CuIcenters and the N2ligand, they reveal a degree of cooperativity in the dinuclear Cu‐N2‐Cu interaction. Addition of MeCN, CNAr2,6‐Me, or O2to3releases N2with formation ofiPr2TpCu(L) (L=NCMe, CNAr2,6‐Me2) or [iPr2TpCu]2(μ‐η22‐O2) (1). Addition of triphenylsilane to [iPr2TpCu]2(μ‐OH)2in pentane allows isolation of a key intermediate [iPr2TpCu]2(μ‐H) (5). Although5thermally decays under N2to give3, it reduces unsaturated substrates, such as CO and HC≡CPh to HC(O)H and H2C=CHPh, respectively.

     
    more » « less
  2. Abstract

    With the goal of generating anionic analogues to MN2S2Mn(CO)3Br we introduced metallodithiolate ligands, MN2S22−prepared from the Cys‐X‐Cys biomimetic, ema4−ligand (ema=N,N′‐ethylenebis(mercaptoacetamide); M=NiII, [VIV≡O]2+and FeIII) to Mn(CO)5Br. An unexpected, remarkably stable dimanganese product, (H2N2(CH2C=O(μ‐S))2)[Mn(CO)3]2resulted from loss of M originally residing in the N2S24−pocket, replaced by protonation at the amido nitrogens, generating H2ema2−. Accordingly, the ema ligand has switched its coordination mode from an N2S24−cavity holding a single metal, to a binucleating H2ema2−with bridging sulfurs and carboxamide oxygens within Mn‐μ‐S‐CH2‐C‐O, 5‐membered rings. In situ metal‐templating by zinc ions gives quantitative yields of the Mn2product. By computational studies we compared the conformations of “linear” ema4−to ema4−frozen in the “tight‐loop” around single metals, and to the “looser” fold possible for H2ema2−that is the optimal arrangement for binucleation. XRD molecular structures show extensive H‐bonding at the amido‐nitrogen protons in the solid state.

     
    more » « less
  3. Abstract

    With the goal of generating anionic analogues to MN2S2Mn(CO)3Br we introduced metallodithiolate ligands, MN2S22−prepared from the Cys‐X‐Cys biomimetic, ema4−ligand (ema=N,N′‐ethylenebis(mercaptoacetamide); M=NiII, [VIV≡O]2+and FeIII) to Mn(CO)5Br. An unexpected, remarkably stable dimanganese product, (H2N2(CH2C=O(μ‐S))2)[Mn(CO)3]2resulted from loss of M originally residing in the N2S24−pocket, replaced by protonation at the amido nitrogens, generating H2ema2−. Accordingly, the ema ligand has switched its coordination mode from an N2S24−cavity holding a single metal, to a binucleating H2ema2−with bridging sulfurs and carboxamide oxygens within Mn‐μ‐S‐CH2‐C‐O, 5‐membered rings. In situ metal‐templating by zinc ions gives quantitative yields of the Mn2product. By computational studies we compared the conformations of “linear” ema4−to ema4−frozen in the “tight‐loop” around single metals, and to the “looser” fold possible for H2ema2−that is the optimal arrangement for binucleation. XRD molecular structures show extensive H‐bonding at the amido‐nitrogen protons in the solid state.

     
    more » « less
  4. Abstract

    With the intent to demonstrate that the charge of Z‐type ligands can be used to modulate the electrophilic character and catalytic properties of coordinated transition metals, we are now targeting complexes bearing polycationic antimony‐based Z‐type ligands. Toward this end, the dangling phosphine arm of ((o‐(Ph2P)C6H4)3)SbCl2AuCl (1) was oxidized with hydrogen peroxide to afford [((o‐(Ph2P)C6H4)2(o‐Ph2PO)C6H4)SbAuCl2]+([2 a]+) which was readily converted into the dicationic complex [((o‐(Ph2P)C6H4)2(o‐Ph2PO)C6H4)SbAuCl]2+([3]2+) by treatment with 2 equiv AgNTf2. Both experimental and computational results show that [3]2+possess a strong Au→Sb interaction reinforced by the dicationic character of the antimony center. The gold‐bound chloride anion of [3]2+is rather inert and necessitates the addition of excess AgNTf2to undergo activation. The activated complex, referred to as [4]2+[((o‐(Ph2P)C6H4)2(o‐Ph2PO)C6H4)SbAuNTf2]2+readily catalyzes both the polymerization and the hydroamination of styrene. This atypical reactivity underscores the strong σ‐accepting properties of the dicationic antimony ligand and its activating impact on the gold center.

     
    more » « less
  5. Abstract

    With the intent to demonstrate that the charge of Z‐type ligands can be used to modulate the electrophilic character and catalytic properties of coordinated transition metals, we are now targeting complexes bearing polycationic antimony‐based Z‐type ligands. Toward this end, the dangling phosphine arm of ((o‐(Ph2P)C6H4)3)SbCl2AuCl (1) was oxidized with hydrogen peroxide to afford [((o‐(Ph2P)C6H4)2(o‐Ph2PO)C6H4)SbAuCl2]+([2 a]+) which was readily converted into the dicationic complex [((o‐(Ph2P)C6H4)2(o‐Ph2PO)C6H4)SbAuCl]2+([3]2+) by treatment with 2 equiv AgNTf2. Both experimental and computational results show that [3]2+possess a strong Au→Sb interaction reinforced by the dicationic character of the antimony center. The gold‐bound chloride anion of [3]2+is rather inert and necessitates the addition of excess AgNTf2to undergo activation. The activated complex, referred to as [4]2+[((o‐(Ph2P)C6H4)2(o‐Ph2PO)C6H4)SbAuNTf2]2+readily catalyzes both the polymerization and the hydroamination of styrene. This atypical reactivity underscores the strong σ‐accepting properties of the dicationic antimony ligand and its activating impact on the gold center.

     
    more » « less