Synthesis, Structure and Bonding Analysis of the Zwitterionic PPP-Pincer Complex (6-Ph2P-Ace-5-)2P(O)AuCl2

The reaction of (6-Ph2P-Ace-5-)2P(O)H with (tht)AuCl3proceeds via elimination oftetrahydrothiophene (tht) and HCl, providing the zwitterionic PPP-pincer complex (6-Ph2P-Ace-5-)2P(O)AuCl2(1) as yellow crystals. The molecular structure of1was established and studied by X-raycrystallography. The electronic structure was computationally analyzed using a comprehensiveset of real-space bonding indicators derived from electron and electron-pair densities, providinginsight into the relative contributions of covalent and non-covalent forces to the polar-covalent Au–Cl,Au–P, and P–O−bonds; the latter being one of the textbook cases for strongly polarized covalentinteractions. Partial spatial complementarity between both bonding aspects is suggested by theelectronic properties of the distinctively different Au–Cl bonds

Kinetic Stabilization of Heavier Bis(m-terphenyl)pnictogen Phosphaethynolates

Kinetic stabilization using bulky m-terphenyl substituents is the key to the isolation of the diarylantimony and diarylbismuth phosphaethynolates (2,6-Mes2C6H3)2EPCO and the related N-heterocyclic carbene complexes (2,6-Mes2C6H3)2EP(O)C(IMe4) (E=Sb, Bi; IMe4=1,3,4,5-tetramethylimidazol-2-ylidene), which have been fully characterized crystallographically and spectroscopically. The experimental characterization was augmented by a DFT based real space bond indicator analysis of the electron density, including AIM, NCI, and ELI-D methods

Silyl Cations Stabilized by Pincer Type Ligands with Adjustable Donor Atoms

Novel E,C,E'-pincer supported silyl cations (E, E' = O, S, Se, Au) were prepared in three steps starting from 2,6-F2C6H3SiMe2H (1a) and 2,6-Br2C6H3SiMe2H (1b), which were first converted in two complementary ways into 2,6-(Ph2P)(2)C6H3SiMe2H (2). The oxidation of 2 with H2O2 center dot urea, S-8, and Se-8 afforded 2,6-(Ph2PE)(2)C6H3SiMe2H (3a, E = O; 3b, E = S; 3c, E = Se) and 2-(Ph2PE)-6-(Ph2P)-C6H3SiMe2H (4b, E = S; 4c, E = Se), which were reacted to the E,C,E-supported silyl cations [2,6-(Ph2PE)(2)C6H3SiMe2](+) (5a, E = O, counterion Br-3(-); 5b, E = S, counterion B(C6F5)(4)(-); 5c, E = Se, counterion B(C6F5)(4)(-)), the E,C-supported silyl cations [2-(Ph2PE)-6-(Ph2P)C6H3SiMe2](+) (6b, E = S, not isolated; 6c, E = Se, not isolated), the O,C,S-supported silyl cation [2-(Ph2PS)-6-(Ph2PO)C6H3SiMe2](+) (7, counterion B(C6F5)(4)(-)) as well as the E,C,Au-supported silyl cations [2-(Ph2PAuC6F5)-6-(Ph2PE)C6H3SiMe2](+) (8b, E = S, counterion [B{3,5-(CF3)(2)C6H3}(4)](-); 8c, E = Se, [B{3,5-(CF3)(2)C6H3}(4)](-)) using Br-2, O-2, S-8, (tht)AuC6F5, Ph3C[B(C6F5)(4)] and Ph3C[B{3,5-(CF3)(2)C6H3}(4)]. All compounds were characterized by multinuclear (H-1, C-13, F-19, Si-29, P-31, Se-77) NMR spectroscopy, ESI MS spectrometry and X-ray crystallography (2, 3a center dot H2O, 3b, 3c, 4b, 5a, 5c, 7, 8b, 8c). The gas phase structures of 2, 3a-c, 5a-c (fully optimized) and 8b, 8c (single-point calculations) were studied at the B3PW91/6-311+G(2df,p) level of theory. A set of real-space bonding indicators (RSBIs) derived from the theoretically calculated electron and pair densities were analyzed utilizing the atoms-in molecules (AIM) and electron-localizability indicator (ELI-D) space partitioning schemes

Conformational trimorphism of bis(2,6-dimesitylphenyl)ditelluride

Besides the previously known α-form (monoclinic, P21/c, Z=4) of bis(2,6-dimesitylphenyl)ditelluride, two new polymorphic modifications, namely the β-form (monoclinic, P21/c, Z=8) and the γ-form (triclinic, P1̅, Z=2), were obtained serendipitously during chemical reactions. In all three modifications, the individual molecules possess significantly different conformations and bond parameters, such as Te–Te bond lengths, C–Te–Te bond angles, C–Te–Te–C torsion angles and intramolecular Menshutkin interactions, which is also reflected in their non-covalent interactions with adjacent molecules in the crystal lattice via London dispersion and electrostatic forces. The interplay between intermolecular and intramolecular forces in these conformational polymorphs was investigated using quantum chemical calculations, which reveal that the β-form should be thermodynamically stable at absolute zero. In contrast, crystallization experiments and thermoanalytical investigations indicate that the α-form is stable at high temperatures and therefore, both forms might be related by enantiotropis

Bis(6-diphenylphosphino-acenaphth-5-yl)sulfoxide. A New Ligand for Late Transition Metal Complexes

The synthesis of the new ligand bis(6-diphenylphosphinoacenaphth-5-yl)sulfoxide, [6-(Ph2P)-5-Ace-6](2)-SO (1), is presented along with six transition metal complexes thereof, namely,1 center dot MCl (M = Rh, Cu, Ag, Au) and1 center dot MCl2(M = Ni, Pd). Within these novel complexes, close metal-sulfur distances are observed and the nature of the M-S coordination, as well as the response of the(+)S-O(-)bond, are investigated in detail with a set of spectroscopic, crystallographic and real-space bonding indicators

Increasing the Brønsted acidity of Ph2PO2H by the Lewis acid B(C6F5)3. Formation of an eight-membered boraphosphinate ring [Ph2POB(C6F5)2O]2

The Deutsche Forschungsgemeinschaft (DFG) is gratefully acknowledged for financial support. The theoretical part of this work was supported by the Russian Science Foundation (Project 14-13-00832).Autoprotolysis of the metastable acid (C6F5)3BOPPh2OH, prepared in situ by the reaction of the rather weak Brønsted acid Ph2PO2H with the strong Lewis acid B(C6F5)3, gave rise to the formation of the eight-membered ring [Ph2POB(C6F5)2O]2 and C6F5H. The conjugate base was isolated as stable sodium crown ether salt [Na(15-crown-5)][Ph2PO2B(C6F5)3].Publisher PDFPeer reviewe

Peri-substituted phosphorus-tellurium systems – an experimental and theoretical investigation of the P∙∙∙Te through-space interaction

The authors are thankful to the EPSRC, the EPSRC National Mass Spectrometry Service Centre (NMSSC) Swansea, the School of Chemistry St. Andrews, and EaStCHEM for support.A series of peri-substituted phosphorus-tellurium systems R’Te–Acenap–PR2 (R’ = Ph, p-An, Nap, Mes, Tip; R = iPr, Ph) exhibiting large “through space” spin-spin coupling constants and the “onset” of three-centre four-electron type interactions are presented. The influence of the substituents at the phosphorus and tellurium atoms as well as their behavior upon oxidation (with S, Se) or metal-coordination (Pt, Au) is discussed using NMR spectroscopy, single crystal X-ray diffraction, and advanced DFT studies including NBO, AIM and ELI-D analyses.PostprintPeer reviewe