Insertion of a Nontrigonal Phosphorus Ligand into a Transition Metal-Hydride: Direct Access to a Metallohydrophosphorane

The synthesis and reactivity of an NPN-chelating ligand containing a nontrigonal phosphorous triamide center (<b>L1</b> = P­(N­(<i>o</i>-N­(2-pyridyl)­C₆H₄)₂) is reported. Metalation of <b>L1</b> with RuCl₂(PPh₃)₃ gives RuCl₂(PPh₃)­(<b>L1</b>) (<b>2</b>). By contrast, metalation of <b>L1</b> with RuHCl­(CO)­(PPh₃)₃ yields RuCl­(CO)­(PPh₃)­(<b>L1</b>^H) (<b>3</b>), a chelated 10-P-5 ruthenahydridophosphorane, via net insertion into the Ru–H bond. Hydride abstraction from <b>3</b> with Ph₃CPF₆ gives [RuCl­(CO)­(PPh₃)­(<b>L1</b>)]­PF₆ (<b>4</b>); reaction of <b>4</b> with NaBH₄ returns <b>3.</b

Insertion of a Nontrigonal Phosphorus Ligand into a Transition Metal-Hydride: Direct Access to a Metallohydrophosphorane

The synthesis and reactivity of an NPN-chelating ligand containing a nontrigonal phosphorous triamide center (<b>L1</b> = P­(N­(<i>o</i>-N­(2-pyridyl)­C₆H₄)₂) is reported. Metalation of <b>L1</b> with RuCl₂(PPh₃)₃ gives RuCl₂(PPh₃)­(<b>L1</b>) (<b>2</b>). By contrast, metalation of <b>L1</b> with RuHCl­(CO)­(PPh₃)₃ yields RuCl­(CO)­(PPh₃)­(<b>L1</b>^H) (<b>3</b>), a chelated 10-P-5 ruthenahydridophosphorane, via net insertion into the Ru–H bond. Hydride abstraction from <b>3</b> with Ph₃CPF₆ gives [RuCl­(CO)­(PPh₃)­(<b>L1</b>)]­PF₆ (<b>4</b>); reaction of <b>4</b> with NaBH₄ returns <b>3.</b

Insertion of a Nontrigonal Phosphorus Ligand into a Transition Metal-Hydride: Direct Access to a Metallohydrophosphorane

The synthesis and reactivity of an NPN-chelating ligand containing a nontrigonal phosphorous triamide center (<b>L1</b> = P­(N­(<i>o</i>-N­(2-pyridyl)­C₆H₄)₂) is reported. Metalation of <b>L1</b> with RuCl₂(PPh₃)₃ gives RuCl₂(PPh₃)­(<b>L1</b>) (<b>2</b>). By contrast, metalation of <b>L1</b> with RuHCl­(CO)­(PPh₃)₃ yields RuCl­(CO)­(PPh₃)­(<b>L1</b>^H) (<b>3</b>), a chelated 10-P-5 ruthenahydridophosphorane, via net insertion into the Ru–H bond. Hydride abstraction from <b>3</b> with Ph₃CPF₆ gives [RuCl­(CO)­(PPh₃)­(<b>L1</b>)]­PF₆ (<b>4</b>); reaction of <b>4</b> with NaBH₄ returns <b>3.</b

Insertion of a Nontrigonal Phosphorus Ligand into a Transition Metal-Hydride: Direct Access to a Metallohydrophosphorane

The synthesis and reactivity of an NPN-chelating ligand containing a nontrigonal phosphorous triamide center (<b>L1</b> = P­(N­(<i>o</i>-N­(2-pyridyl)­C₆H₄)₂) is reported. Metalation of <b>L1</b> with RuCl₂(PPh₃)₃ gives RuCl₂(PPh₃)­(<b>L1</b>) (<b>2</b>). By contrast, metalation of <b>L1</b> with RuHCl­(CO)­(PPh₃)₃ yields RuCl­(CO)­(PPh₃)­(<b>L1</b>^H) (<b>3</b>), a chelated 10-P-5 ruthenahydridophosphorane, via net insertion into the Ru–H bond. Hydride abstraction from <b>3</b> with Ph₃CPF₆ gives [RuCl­(CO)­(PPh₃)­(<b>L1</b>)]­PF₆ (<b>4</b>); reaction of <b>4</b> with NaBH₄ returns <b>3.</b

Intramolecular Ferromagnetic Radical–Cu^II Coupling in a Cu^II Complex Ligated with Pyridyl-Substituted Triarylmethyl Radicals

Novel metal complexes M­(hfac)₂(PyBTM)₂ [M = Cu^II, Zn^II; hfac = hexafluoroacetylacetonato; PyBTM = (3,5-dichloro-4-pyridyl)­bis­(2,4,6-trichlorophenyl)­methyl radical] were prepared. Both hexacoordinated complexes had elongated octahedral geometry, in which two PyBTM molecules coordinated at the equatorial positions in Cu^II(hfac)₂(PyBTM)₂ but at the axial positions in Zn^II(hfac)₂(PyBTM)₂. Magnetic studies revealed an intramolecular ferromagnetic exchange interaction between the spins on PyBTM and Cu^II (<i>J</i>_Cu–R/<i>k</i>_B = 47 K) based on the orthogonality of the two spin orbitals

Metal–Ligand Role Reversal: Hydride-Transfer Catalysis by a Functional Phosphorus Ligand with a Spectator Metal

Hydride transfer catalysis is shown to be enabled by the nonspectator reactivity of a transition metal-bound low-symmetry tricoordinate phosphorus ligand. Complex 1·[Ru]+, comprising a nontrigonal phosphorus chelate (1, P(N(o-N(2-pyridyl)C6H4)2) and an inert metal fragment ([Ru] = (Me5C5)Ru), reacts with NaBH4 to give a metallohydridophosphorane (1H·[Ru]) by P–H bond formation. Complex 1H·[Ru] is revealed to be a potent hydride donor (ΔG°H–,exp G°H–,calc = 38 ± 2 kcal/mol in MeCN). Taken together, the reactivity of the 1·[Ru]+/1H·[Ru] pair comprises a catalytic couple, enabling catalytic hydrodechlorination in which phosphorus is the sole reactive site of hydride transfer

Spin-Reconstructed Proton-Coupled Electron Transfer in a Ferrocene–Nickeladithiolene Hybrid

A proton–electron dual-responsive system based on a hybrid of ferrocene and metalladithiolene (<b>1</b>) was developed. The formation of the dithiafulvenium moiety was driven by protonation of the metalladithiolene unit of <b>1</b> and by oxidation. The change in the electronic structure caused by the protonation was combined with the redox properties of the two components of <b>1</b>, generating two radical species with different spin density distributions (3d spin and π spin). Furthermore, a spin-reconstructed proton-coupled electron transfer, i.e., the transformation from 3d spin to π spin accompanied by deprotonation, was achieved by a temperature change, the third external stimulus