2',2''-Di-O-methyltenuiorin

In the title compound, C19H17Cl2N3O2, there are three mol-ecules (A, B and C) in the asymmetric unit and each differs in the conformation adopted. As a result of steric repulsion, the amide group is rotated with respect to both the dichloro-phenyl and 2,3-dihydro-1H-pyrazol-4-yl rings, making dihedral angles of 44.5 (2) and 56.2 (2)°, respectively in A, 51.1 (2) and 54.1 (2)° in B, and 53.8 (2) and 54.6 (2)° in C. The dihedral angles between the dichloro-phenyl and 2,3-dihydro-1H-pyrazol-4-yl rings are 54.8 (2), 76.2 (2) and 77.5 (2)° in mol-ecules A, B and C, respectively, while the 2,3-dihydro-1H-pyrazol-4-yl and phenyl rings make dihedral angles of 45.3 (2), 51.2 (2) and 42.8 (2)°, respectively. In the crystal, two of the mol-ecules are linked through N-H⋯O hydrogen bonding to an adjoining mol-ecule, forming dimers of the R2(2)(10) type, while the third mol-ecule forms such dimers with itself. C-H⋯O inter-actions link the dimers.

The water reactivity of the boroauride complex ([Au(B2P2)][K(18-c-6)]; (B2P2, 9,10-bis(2-(diisopropylphosphino)-phenyl)-9,10-dihydroboranthrene) and its corresponding two-electron oxidized complex, Au(B2P2)Cl, are presented. Au(B2P2)Cl is tolerant to H2O and forms the hydroxide complex Au(B2P2)OH in the presence of H2O and triethylamine. [Au(B2P2)]Cl and [Au(B2P2)]OH are poor Lewis acids as judged by the Gutmann-Becket method, with [Au(B2P2)]OH displaying facile hydroxide exchange between B atoms of the DBA ring as evidenced by variable temperature NMR spectroscopy. The reduced boroauride complex [Au(B2P2)]- reacts with 1 equivalent of H2O to produce a hydride/hydroxide product, [Au(B2P2)(H)(OH)]-, that rapidly evolves H2 upon further H2O reaction to yield the dihydroxide compound, [Au(B2P2)(OH)2]-. [Au(B2P2)]Cl can be regenerated from [Au(B2P2)(OH)2]-via HCl·Et2O, providing a synthetic cycle for H2 evolution from H2O enabled by O-H oxidative addition at a diboraanthracene unit.

We report two novel titanium-based pnictide oxide compounds (EuF)2Ti2Pn2O (Pn = Sb, Bi), which are synthesized by replacing Sr2+ in (SrF)2Ti2Pn2O [Liu, R. H. Structure and Physical Properties of the Layered Pnictide-Oxides: (SrF)2Ti2Pn2O (Pn = As, Sb) and (SmO)2Ti2Sb2O. Chem. Mater. 2010, 22, 1503-1508] with Eu2+ using a solid-state reaction. (EuF)2Ti2Sb2O exhibits an obvious anomaly in resistivity and heat capacity at T ~ 195 K, which may arise from the spin-density wave/charge-density wave instability. Similar features are also observed in BaTi2Pn2O, (SrF)2Ti2Pn2O, and Na2Ti2Pn2O (Pn = As and Sb) [Liu, R. H. Structure and Physical Properties of the Layered Pnictide-Oxides: (SrF)2Ti2Pn2O (Pn = As, Sb) and (SmO)2Ti2Sb2O. Chem. Mater. 2010, 22, 1503-1508, Ozawa, T. C. Chemistry of layered d-metal pnictide oxides and their potential as candidates for new superconductors. Sci. Technol. Adv. Mater. 2008, 9, 033003, Wang, X. F. Structure and physical properties for a new layered pnictide-oxide: BaTi2As2O. J. Phys.: Condens. Matter. 2010, 22, 075702, and Xu, H. C. Electronic structure of the BaTi2As2O parent compound of the titanium-based oxypnictide superconductor. Phys. Rev. B 2014, 89, 155108]. Magnetic susceptibility measurements indicate an antiferromagnetic transition at T ~ 2.5 K for (EuF)2Ti2Sb2O. In particular, the electronic specific heat coefficients of both (EuF)2Ti2Sb2O and (EuF)2Ti2Bi2O are significantly enhanced compared to those of (SrF)2Ti2Pn2O, Na2Ti2Pn2O, and BaTi2Pn2O,1,5,6 which may be due to a strong electron correlation effect in this system. Thus, (EuF)2Ti2Pn2O (Pn = Sb, Bi) may provide new platforms for studying density wave, magnetic ordering, and electron correlation effects.