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1. Synthesis, Structure, and Bonding of d 3 Molybdenum–Oxo Complexes

   https://doi.org/10.1002/ange.202001379  

   Vibbert, Hunter B. ; Filatov, Alexander S. ; Hopkins, Michael D. ( April 2020 , Angewandte Chemie)

   Reduction of d²metal–oxo ions of the form [MO(PP)₂Cl]⁺(M=Mo, W; PP=chelating diphosphine) produces d³MO(PP)₂Cl complexes, which include the first isolated examples in group 6. The stability and reactivity of the MO(PP)₂Cl compounds are found to depend upon the steric bulk of the phosphine ligands: derivatives with bulky phosphines that shield the oxo ligand are stable enough to be isolated, whereas those with phosphines that leave the oxo ligand exposed are more reactive and observed transiently. Magnetic measurements and DFT calculations on MoO(dppe)₂Cl indicate the d³compounds are low spin with a²[(d_xy)²(π*(MoO))¹] configuration. X‐ray crystallographic and vibrational‐spectroscopic studies on d²and d³[MoO(dppe)₂Cl]^0/+establish that the d³compound possesses a reduced M−O bond order and significantly longer Mo−O bond, accounting for its greater reactivity. These results indicate that the oxo‐centered reactivity of d³complexes may be controlled through ligand variation.

    

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2. Organo‐Functionalized Lacunary Double Cubane‐Type Oxometallates: Synthesis, Structure, and Properties of [(M II Cl) 2 (V IV O) 2 {((HOCH 2 CH 2 )(H)N(CH 2 CH 2 O))(HN(CH 2 CH 2 O) 2 )} 2 ] (M=Co, Zn)

   https://doi.org/10.1002/chem.202301389  

   Shuaib, Damola T. ; Swenson, LaSalle ; Kaduk, James A. ; Chang, Tieyan ; Chen, Yu‐Sheng ; McNeely, James ; Khan, M. Ishaque ( October 2023 , Chemistry – A European Journal)

   Organofunctionalized tetranuclear clusters [(M^IICl)₂(V^IVO)₂{((HOCH₂CH₂)(H)N(CH₂CH₂O))(HN(CH₂CH₂O)₂)}₂] (1, M=Co,2: M=Zn) containing an unprecedented oxometallacyclic {M₂V₂Cl₂N₄O₈} (M=Co, Zn) framework have been prepared by solvothermal reactions. The new oxo‐alkoxide compounds were fully characterized by spectroscopic methods, magnetic susceptibility measurement, DFT and ab initio computational methods, and complete single‐crystal X‐ray diffraction structure analysis. The isostructural clusters are formed of edge‐sharing octahedral {VO₅N} and trigonal bipyramidal {MO₃NCl} units. Diethanolamine ligates the bimetallic lacunary double cubane core of1and2in an unusual two‐mode fashion, unobserved previously. In the crystalline state, the clusters of1and2are joined by hydrogen bonds to form a three‐dimensional network structure. Magnetic susceptibility data indicate weakly antiferromagnetic interactions between the vanadium centers [J_iso(V^IV−V^IV)=−5.4(1); −3.9(2) cm⁻¹], and inequivalent antiferromagnetic interactions between the cobalt and vanadium centers [J_iso(V^IV−Co^II)=−12.6 and −7.5 cm⁻¹] contained in1.

    

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3. Photodriven Elimination of Chlorine From Germanium and Platinum in a Dinuclear Pt II →Ge IV Complex

   https://doi.org/10.1002/ange.202107485  

   Karimi, Mohammadjavad ; Tabei, Elham S. ; Fayad, Remi ; Saber, Mohamed R. ; Danilov, Evgeny O. ; Jones, Cameron ; Castellano, Felix N. ; Gabbaï, François P. ( September 2021 , Angewandte Chemie)

   Searching for a connection between the two‐electron redox behavior of Group‐14 elements and their possible use as platforms for the photoreductive elimination of chlorine, we have studied the photochemistry of [(o‐(Ph₂P)C₆H₄)₂Ge^IVCl₂]Pt^IICl₂and [(o‐(Ph₂P)C₆H₄)₂ClGe^III]Pt^IIICl₃, two newly isolated isomeric complexes. These studies show that, in the presence of a chlorine trap, both isomers convert cleanly into the platinum germyl complex [(o‐(Ph₂P)C₆H₄)₂ClGe^III]Pt^ICl with quantum yields of 1.7 % and 3.2 % for the Ge^IV–Pt^IIand Ge^III–Pt^IIIisomers, respectively. Conversion of the Ge^IV–Pt^IIisomer into the platinum germyl complex is a rare example of a light‐induced transition‐metal/main‐group‐element bond‐forming process. Finally, transient‐absorption‐spectroscopy studies carried out on the Ge^III–Pt^IIIisomer point to a ligand arene–Cl^.charge‐transfer complex as an intermediate.

    

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4. Photodriven Elimination of Chlorine From Germanium and Platinum in a Dinuclear Pt II →Ge IV Complex

   https://doi.org/10.1002/anie.202107485  

   Karimi, Mohammadjavad ; Tabei, Elham S. ; Fayad, Remi ; Saber, Mohamed R. ; Danilov, Evgeny O. ; Jones, Cameron ; Castellano, Felix N. ; Gabbaï, François P. ( September 2021 , Angewandte Chemie International Edition)

   Searching for a connection between the two‐electron redox behavior of Group‐14 elements and their possible use as platforms for the photoreductive elimination of chlorine, we have studied the photochemistry of [(o‐(Ph₂P)C₆H₄)₂Ge^IVCl₂]Pt^IICl₂and [(o‐(Ph₂P)C₆H₄)₂ClGe^III]Pt^IIICl₃, two newly isolated isomeric complexes. These studies show that, in the presence of a chlorine trap, both isomers convert cleanly into the platinum germyl complex [(o‐(Ph₂P)C₆H₄)₂ClGe^III]Pt^ICl with quantum yields of 1.7 % and 3.2 % for the Ge^IV–Pt^IIand Ge^III–Pt^IIIisomers, respectively. Conversion of the Ge^IV–Pt^IIisomer into the platinum germyl complex is a rare example of a light‐induced transition‐metal/main‐group‐element bond‐forming process. Finally, transient‐absorption‐spectroscopy studies carried out on the Ge^III–Pt^IIIisomer point to a ligand arene–Cl^.charge‐transfer complex as an intermediate.

    

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5. Reaction Pathway for the Aerobic Oxidation of Phosphines Catalyzed by Oxomolybdenum Salen Complexes

   https://doi.org/10.1002/ejic.202300506  

   Rusmore, Theo A. ; Lander, Chance ; Nicholas, Kenneth M. ( December 2023 , European Journal of Inorganic Chemistry)

   Catalysis ofO‐atom transfer (OAT) reactions is a characteristic of both natural (enzymatic) and synthetic molybdenum‐oxo and ‐peroxo complexes. These reactions can employ a variety of terminal oxidants, e. g. DMSO,N‐oxides, and peroxides, etc., but rarely molecular oxygen. Here we demonstrate the ability of a set of Schiff‐base‐MoO₂complexes (cy‐salen)MoO₂(cy‐salen=N,N’‐cyclohexyl‐1,2‐bis‐salicylimine) to catalyze the aerobic oxidation of PPh₃. We also report the results of a DFT computational investigation of the catalytic pathway, including the identification of energetically accessible intermediates and transition states, for the aerobic oxidation of PMe₃. Starting from the dioxo species, (cy‐salen)Mo(VI)O₂(1), key reaction steps include: 1) associative addition of PMe₃to an oxo‐O to give LMo(IV)(O)(OPMe₃) (2); 2) OPMe₃dissociation from2to produce mono‐oxo complex (cy‐salen)Mo(IV)O (3); 3) stepwise O₂association with3via superoxo species (cy‐salen)Mo(V)(O)(η¹‐O₂) (4) to form the oxo‐peroxo intermediate (cy‐salen)Mo(VI)(O)(η²‐O₂) (5); 4) theO‐transfer reaction of PMe₃with oxo‐peroxo species5at the oxo‐group, rather than the peroxo unit leading, after OPMe₃dissociation, to a monoperoxo species, (cy‐salen)Mo(IV)(η²‐O₂) (7); and 5) regeneration of the dioxo complex (cy‐salen)Mo(VI)O₂(1) from the monoperoxo triplet³7or singlet¹7by a concerted, asynchronous electronic isomerization. An alternative pathway for recycling of the oxo‐peroxo species5to the dioxo‐Mo1via a bimetallic peroxo complex LMo(O)‐O−O‐Mo(O)L8is determined to be energetically viable, but is unlikely to be competitive with the primary pathway for aerobic phosphine oxidation catalyzed by1.

    

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