Haijun Hao

Syntheses and structures of the first examples of zinc compounds with bridging fluorine and hydrogen atoms

The first examples of zinc compounds with bridging fluorine and hydrogen atoms [{HC(CMeNAr)2}Zn(μ-X)]2 (Ar = 2,6-Me2C6H3, X = F, 8; X = H, 9) have been synthesised and structurally characterised.

Bis(arylimido) Molybdenum(VI) Amidinate and Guanidinate Complexes; Molecular Structures of [(ArN)2MoMe{N(Cy)C[N(i-Pr)2]N(Cy)}] (Ar = 2,6-i-Pr2C6H3; Cy = Cyclohexyl) and [(2,6-i-Pr2C6H3N)2MoCl2] · [NH=C(C6H5)CH(SiMe3)2]

The reaction of [(ArN)2MoCl2] · DME (Ar = 2,6-i-Pr2C6H3) (1) with lithium amidinates or guanidinates resulted in molybdenum(VI) complexes [(ArN)2MoCl{N(R1)C(R2)N(R1)}] (R1 = Cy (cyclohexyl), R2 = Me (2); R1 = Cy, R2 = N(i-Pr)2 (3); R1 = Cy, R2 = N(SiMe3)2 (4); R1 = SiMe3, R2 = C6H5 (5)) with five coordinated molybdenum atoms. Methylation of these compounds was exemplified by the reactions of 2 and 3 with MeLi affording the corresponding methylates [(ArN)2MoMe{N(R1)C(R2)N(R1)}] (R1 = Cy, R2 = Me (6); R1 = Cy, R2 = N(i-Pr)2 (7)). The analogous reaction of 1 with bulky [N(SiMe3)C(C6H5)C(SiMe3)2]Li · THF did not give the corresponding metathesis product, but a Schiff base adduct [(ArN)2MoCl2] · [NH=C(C6H5)CH(SiMe3)2] (8) in low yield. The molecular structures of 7 and 8 are established by the X-ray single crystal structural analysis. Bis(arylimido) Molybdan(VI) Amidinat und Guanidinat Komplexe; Strukturbestimmungen von [(ArN)2MoMe{N(Cy)C[N(i-Pr)2]N(Cy)}] (Ar = 2,6-i-Pr2C6H3; Cy = Cyclohexyl) und [(2,6-i-Pr2C6H3N)2MoCl2] · [NH=C(C6H5)CH(SiMe3)2] Die Umsetzungen von [(ArN)2MoCl2] · DME (Ar = 2,6-i-Pr2C6H3) (1) mit Lithium- Amidinaten oder Guanidinaten lieferten Molybdan(VI) Komplexe [(ArN)2MoCl{N(R1)C(R2)N(R1)}] (R1 = Cy (Cyclohexyl), R2 = Me (2); R1 = Cy, R2 = N(i-Pr)2 (3); R1 = Cy, R2 = N(SiMe3)2 (4); R1 = SiMe3, R2 = C6H5 (5)) mit funffach koordinierten Molybdan Atomen. Durch die Reaktion von 1 und 2 mit MeLi wurden die entsprechenden Methylate [(ArN)2MoMe{N(R1)C(R2)N(R1)}] (R1 = Cy, R2 = Me (6); R1 = Cy, R2 = N(i-Pr)2 (7)) erhalten. In einer analogen Reaktion von 1 mit dem sterisch anspruchsvollen Lithiumsalz des 1-Azaallylliganden [N(SiMe3)C(C6H5)C(SiMe3)2]Li · THF konnte nicht das entsprechende Metatheseprodukt, sondern ein Addukt an die Schiffsche Base in geringer Ausbeute dargestellt werden [(ArN)2MoCl2] · [NH=C(C6H5)CH(SiMe3)2] (8). 7 und 8 wurden durch Einkristallrontgenstrukturanalysen charakterisiert.

Synthesis and characterization of 1-aza-allyl complexes of aluminum, gallium and bismuth

Abstract Bis(1-aza-allyl) aluminum compounds of formula R′2AlY (Y=Cl (1), Me (2); R′=N(SiMe3)C(But)CH(SiMe3)) were obtained in good yields by the reaction of (LiR′)2 with equivalent amounts of AlCl3 and AlMeCl2, respectively, in diethyl ether. The reaction of compound 1 with one equivalent of AlCl3 in toluene afforded the ionic species [R′2Al][AlCl4] (3). Treatment of RLi·THF (R=N(SiMe3)C(Ph)C(SiMe3)2) with GaCl3 and BiBr3 yielded mono(1-aza-allyl) complexes RGaCl2 (4) and RBiBr2 (5), respectively. Complexes 1, 2, 4 and 5 have been characterized by multinuclear NMR spectroscopy, mass spectroscopy and elemental analysis. The characterization of compound 3 is based on multinuclear NMR spectroscopy and physical properties, whereas single crystal X-ray diffraction data are provided for compound 1.

Synthesis and structures of aluminium monohydride and chalcogenides bearing a bidentate [N,O] ligand

The aluminium monohydride (3-tBu-5-Me-2-(O)C(6)H(2)CH(2)-N-2,6-iPr(2)C(6)H(3))AlH(NMe(3))(2) was prepared by treatment of the bidentate salicylaldimine [3-tBu-5-Me-2-(OH)C(6)H(2)CH=N-2,6-iPr(2)C(6)H(3)](1) with a small excess of AlH(3).NMe(3) in high yield. Compound 2 reacted with sulfur and selenium respectively to afford the dimeric aluminium chalcogenide [(3-tBu-5-Me-2-(O)C(6)H(2)CH(2)-NH-2,6-iPr(2)C(6)H(3))Al(micro-E)](2)[E = S (3), E = Se (4)]. During the formation of 2 hydrogen migration from the aluminium centre to the ligand backbone occurred. A possible reaction mechanism for 3 and 4 is discussed and the molecular structures of compounds 2-4 were determined by X-ray structural analyses.