Nickel(II) and nickel(0) complexes of bis(diisopropylphosphino)amine: Synthesis, structure, and electrochemical activity

In its neutral state, bis(diisopropylphosphino)amine HL reacts in equimolar amounts with the nickel halides NiCl2·6H2O, NiBr2, and NiI2in ethanol solutions to give the air- and moisture-stable P,P-chelated complexes (HL)NiX2(X = Cl, Br, I). Under similar conditions, complexes of the form (HL)2NiX2(X = BF4, NO3, ClO4) were prepared from 2:1 ligand-metal ratios of Ni(BF4)2{\textperiodcentered}6H2O, Ni(NO3)2{\textperiodcentered}6H2O, or Ni(ClO4)2{\textperiodcentered}6H2O. Deprotonation of the ligand with NaNH2followed by reaction with NiI2gives L2Ni when performed in Et2O, but leads to the co-crystal L2Ni{\textperiodcentered}2NCCHC(Me)NH2 when the solvent is acetonitrile. In addition to these Ni2+compounds, the Ni0complex (HL)2Ni can be prepared from a toluene solution of Ni(cod)2. Each complex has been characterized by a combination of IR and multi-nuclear NMR spectroscopies, as well as single-crystal X-ray diffraction. Electrochemical studies of the complexes revealed irreversible decomposition of the (HL)NiX2(X = Cl, Br, I) series, but electrocatalytic CO2reduction by the (HL)2NiX2(X = BF4, NO3, ClO4) compounds

Catalytic Synthesis of Superlinear Alkenyl Arenes Using a Rh(I) Catalyst Supported by a “Capping Arene” Ligand: Access to Aerobic Catalysis

Alkyl and alkenyl arenes are used in a wide range of products. However, the synthesis of 1-phenylalkanes or their alkenyl variants from arenes and alkenes is not accessible with current commercial acid-based catalytic processes. Here, it is reported that an air-stable Rh(I) complex, (5-FP)Rh(TFA)(η^2-C_2H_4) (5-FP = 1,2-bis(N-7-azaindolyl)benzene; TFA = trifluoroacetate), serves as a catalyst precursor for the oxidative conversion of arenes and alkenes to alkenyl arenes that are precursors to 1-phenylalkanes upon hydrogenation. It has been demonstrated that coordination of the 5-FP ligand enhances catalyst longevity compared to unligated Rh(I) catalyst precursors, and the 5-FP-ligated catalyst permits in situ recycling of the Cu(II) oxidant using air. The 5-FP ligand provides a Rh catalyst that can maintain activity for arene alkenylation over at least 2 weeks in reactions at 150 °C that involve multiple Cu(II) regeneration steps using air. Conditions to achieve >13 000 catalytic turnovers with an 8:1 linear:branched (L:B) ratio have been demonstrated. In addition, the catalyst is active under aerobic conditions using air as the sole oxidant. At 80 °C, an 18:1 L:B ratio of alkenyl arenes has been observed, but the reaction rate is substantially reduced compared to 150 °C. Quantum mechanics (QM) calculations compare two predicted reaction pathways with the experimental data, showing that an oxidative addition/reductive elimination pathway is energetically favored over a pathway that involves C–H activation by concerted metalation–deprotonation. In addition, our QM computations are consistent with the observed selectivity (11:1) for linear alkenyl arene products

{2,6-Bis[(di-tert-butyl­phosphino)­methyl]­phenyl}chloridonickel(II)

In the title compound, [Ni(C24H43P2)Cl], the Ni atom adopts a distorted square-planar geometry, with the P atoms of the 2,6-bis­[(di-tert-butyl­phosphino)meth­yl]phenyl ligand trans to one another. The P—Ni—P plane is twisted out of the plane of the aromatic ring by 21.97 (6)°

1,3-Bis(phenyl­sufanylmeth­yl)benzene

The complete mol­ecule of the title compound, C20H18S2, is generated by crystallographic mirror symmetry, with two C atoms lying on the mirror plane. All of the independent atoms are contained within two planes defined by the thio­phenyl rings (C6S) and the central phenyl ring with the methyl­ene bridge; the r.m.s deviations of these planes are 0.012 and 0.025 Å, respectively. The two planes are almost perpendicular to one another at a dihedral angle of 80.24 (10)°. Inter­molecular C—H—π inter­actions are present in the crystal structure

[2,6-Bis(di-tert-butyl­phosphinometh­yl)­phen­yl-κ3 P,C 1,P′](nitrato-κO)nickel(II)

The NiII atom in the title compound, [Ni(C24H43P2)(NO3)], adopts a distorted square-planar geometry with the P atoms in a trans arrangement. The compound contains a twofold rotational axis with the nitrate group offset from this axis, except for an O atom of the nitrate group, generating two positions of 50% occupancy for the other atoms of the nitrate group

Cobalt and zinc halide complexes of 4-chloro and 4-methylaniline : syntheses, structures and magnetic behavior

Please read abstract in the article.The Carlson School of Chemistry and Biochemistry, Clark University and the Department of Chemistry, Brandeis University. F. X. would like to acknowledge the funding from the European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement No 701647.http://www.elsevier.com/locate/poly2020-08-01hj2019Chemistr

P,P-Diphenyl-N-(1,1,2,2-tetraphenyl-1λ5-diphosphanylidene)phosphinous amide

The title compound, C36H30NP3, a structural isomer of tris(diphenylphosphino)amine, was unexpectedly isolated as the sole phosphorus-containing product from the reaction of Mg[N(PPh2)2]2(THF)2 (THF is tetrahydrofuran) with CO2. Its identity was confirmed by 31P NMR spectroscopy and single-crystal X-ray diffraction. The geometry at the two P(III) atoms is trigonal pyramidal, while the P(V) atom adopts a distorted tetrahedral geometry

Structures and CO₂ Reactivity of Zinc Complexes of Bis(diisopropyl‑) and Bis(diphenylphosphino)amines

The bis­(phosphino)­amines (R₂P)­NH­(PR′₂) (R = R′ = isopropyl; R = R′ = phenyl; R = isopropyl, R′ = phenyl) react with ZnEt₂ to form complexes with two different structural motifs, either the homoleptic monomeric P,P-chelates Zn­[N­(<i>i</i>-Pr₂P)₂]₂ and Zn­[N­(<i>i</i>-Pr₂P)­(Ph₂P)]₂ or the heteroleptic dimeric Zn₂N₂P₂ heterocycles {EtZn­[N­(PPh₂)₂]}₂ and {EtZn­[N­(PPh₂)­(<i>i</i>-Pr₂P)]}₂. In two cases, CO₂ reacts with these complexes to give adducts Zn­[O₂CP­(<i>i</i>-Pr₂)­NP­(<i>i</i>-Pr₂)]₂ and Zn­[O₂CP­(<i>i</i>-Pr₂)­NPPh₂]­[Ph₂PN­(<i>i</i>-Pr₂P)]­ZnEt₂, similar to adducts formed from the reaction of CO₂ with frustrated Lewis pairs (FLPs). In the other two cases, reaction with CO₂ results in cleavage and rearrangement of the N–P bonds to give either N­(PPh₂)₃ or Ph₂P­(<i>i</i>Pr₂P)­NPPh₂. The zinc complexes and their CO₂ products were characterized with a combination of single crystal X-ray diffraction and multinuclear NMR spectroscopy