- Award ID(s):
- 1800332
- NSF-PAR ID:
- 10330598
- Date Published:
- Journal Name:
- Inorganic Chemistry Frontiers
- ISSN:
- 2052-1553
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Transition metal interactions with Lewis acids (M → Z linkages) are fundamentally interesting and practically important. The most common Z-type ligands contain boron, which contains an NMR active 11 B nucleus. We measured solid-state 11 B{ 1 H} NMR spectra of copper, silver, and gold complexes containing a phosphine substituted 9,10-diboraanthracene ligand (B 2 P 2 ) that contain planar boron centers and weak M → BR 3 linkages ([(B 2 P 2 )M][BAr F 4 ] (M = Cu (1), Ag (2), Au (3)) characterized by large quadrupolar coupling ( C Q ) values (4.4–4.7 MHz) and large span ( Ω ) values (93–139 ppm). However, the solid-state 11 B{ 1 H} NMR spectrum of K[Au(B 2 P 2 )] − (4), which contains tetrahedral borons, is narrow and characterized by small C Q and Ω values. DFT analysis of 1–4 shows that C Q and Ω are expected to be large for planar boron environments and small for tetrahedral boron, and that the presence of a M → BR 3 linkage relates to the reduction in C Q and 11 B NMR shielding properties. Thus solid-state 11 B NMR spectroscopy contains valuable information about M → BR 3 linkages in complexes containing the B 2 P 2 ligand.more » « less
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null (Ed.)Copper( i ) and silver( i ) pyrazolate complexes {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]Cu} 3 and {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]Ag} 3 have been synthesized using the fluorinated 3,5-(diaryl)pyrazole 3,5-(3,5-(CF 3 ) 2 Ph) 2 PzH and copper( i ) oxide and silver( i ) oxide, respectively. The gold( i ) analog was obtained from a reaction between Au(THT)Cl and [3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]H/NaH. The X-ray crystal structures show that the coinage metal complexes {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]M} 3 (M = Cu, Ag, Au) are trinuclear in the solid state. They feature distorted nine-membered M 3 N 6 metallacyclic cores. The M–N distances follow Cu < Au < Ag, which is the trend expected from covalent radii of the corresponding coinage metal ions. The 3,5-(3,5-(CF 3 ) 2 Ph) 2 PzH forms hydrogen bonded trimers in the solid state that are further organized by π-stacking between aryl rings. Solid samples of {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]M} 3 display blue photoluminescence. The copper complex {[3,5-(3,5-(CF 3 ) 2 Ph) 2 Pz]Cu} 3 is an excellent catalyst for mediating azide–alkyne cycloaddition chemistry.more » « less
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Abstract Metalation of the polynucleating ligandF,tbsLH6(1,3,5‐C6H9(NC6H3−4‐F−2‐NSiMe2tBu)3) with two equivalents of Zn(N(SiMe3)2)2affords the dinuclear product (F,tbsLH2)Zn2(
1 ), which can be further deprotonated to yield (F,tbsL)Zn2Li2(OEt2)4(2 ). Transmetalation of2 with NiCl2(py)2yields the heterometallic, trinuclear cluster (F,tbsL)Zn2Ni(py) (3 ). Reduction of3 with KC8affords [KC222][(F,tbsL)Zn2Ni] (4 ) which features a monovalent Ni centre. Addition of 1‐adamantyl azide to4 generates the bridging μ3‐nitrenoid adduct [K(THF)3][(F,tbsL)Zn2Ni(μ3‐NAd)] (5 ). EPR spectroscopy reveals that the anionic cluster possesses a doublet ground state (S =). Cyclic voltammetry of 5 reveals two fully reversible redox events. The dianionic nitrenoid [K2(THF)9][(F,tbsL)Zn2Ni(μ3‐NAd)] (6 ) was isolated and characterized while the neutral redox isomer was observed to undergo both intra‐ and intermolecular H‐atom abstraction processes. Ni K‐edge XAS studies suggest a divalent oxidation state for the Ni centres in both the monoanionic and dianionic [Zn2Ni] nitrenoid complexes. However, DFT analysis suggests Ni‐borne oxidation for5 . -
Abstract Metalation of the polynucleating ligandF,tbsLH6(1,3,5‐C6H9(NC6H3−4‐F−2‐NSiMe2tBu)3) with two equivalents of Zn(N(SiMe3)2)2affords the dinuclear product (F,tbsLH2)Zn2(
1 ), which can be further deprotonated to yield (F,tbsL)Zn2Li2(OEt2)4(2 ). Transmetalation of2 with NiCl2(py)2yields the heterometallic, trinuclear cluster (F,tbsL)Zn2Ni(py) (3 ). Reduction of3 with KC8affords [KC222][(F,tbsL)Zn2Ni] (4 ) which features a monovalent Ni centre. Addition of 1‐adamantyl azide to4 generates the bridging μ3‐nitrenoid adduct [K(THF)3][(F,tbsL)Zn2Ni(μ3‐NAd)] (5 ). EPR spectroscopy reveals that the anionic cluster possesses a doublet ground state (S =). Cyclic voltammetry of 5 reveals two fully reversible redox events. The dianionic nitrenoid [K2(THF)9][(F,tbsL)Zn2Ni(μ3‐NAd)] (6 ) was isolated and characterized while the neutral redox isomer was observed to undergo both intra‐ and intermolecular H‐atom abstraction processes. Ni K‐edge XAS studies suggest a divalent oxidation state for the Ni centres in both the monoanionic and dianionic [Zn2Ni] nitrenoid complexes. However, DFT analysis suggests Ni‐borne oxidation for5 . -
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