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The synthesis and characterization of four new β-ketiminate hafnium(IV) chloride complexes dichloro-bis[4-(phenylamido)pent-3-en-2-one]-hafnium (4a), dichloro-bis[4-(4-methylphenylamido)pent-3-en-2-one]-hafnium (4b), dichloro-bis[4-(4-methoxyphenylamido)pent-3-en-2-one]-hafnium (4c), and dichloro-bis[4-(4-chlorophenylamido)pent-3-en-2-one]-hafnium (4d) are reported. All the complexes (4a–d) were characterized by spectroscopic methods (1H NMR, 13C NMR, IR), and elemental analysis while the compound 4c was further examined by single-crystal X-ray diffraction, revealing that the complex is monomer with the hafnium center in octahedral coordination environment and oxygens of the chelating N–O ligands are trans to each other and the chloride ligands are in a cis arrangement. Volatile trends are established for four new β-ketiminate hafnium(IV) chloride complexes (4a–d). Sublimation enthalpies (ΔHsub) were calculated from thermogravimetric analysis (TGA) data, which show that, the dependence of ΔHsub on the molecular weight (4a–c) and inductive effects from chlorine (4d).

Synthesis and spectral investigation of four novel β-diketiminate hafnium(IV) chloride complexes cis-dichloro-bis(2,4-bis(phenylimino)pent-3-ene)-hafnium (4a), cis-dichloro-bis(2,4-bis(4-methylphenylimino)pent-3-ene)-hafnium (4b), cis-dichloro-bis(2,4-bis(4-methoxyphenylimino)pent-3-ene)-hafnium (4c) and cis-dichloro-bis(2,4-bis(4-chlorophenylimino)pent-3-ene)-hafnium (4d) are reported. All complexes (4a–d) were characterized by spectroscopic methods (1H NMR, 13C NMR and mass) and elemental analysis. The solid-state structure of compound 4a was further examined by single crystal X-ray diffraction. The X-ray structure of 4a reveals that the complex is monomeric with the hafnium center in a distorted octahedral geometry, and the chloride ligands are in a cis arrangement. The thermal stability and volatility of the compounds were probed by TGA/DSC tests demonstrating the potential utility of compounds (4a–d) as precursors for CVD/ALD thin film growth below 200 °C.

Ordered carbonaceous growth typically requires high-energy methods such as arc discharge [1] or decomposition of hydrocarbon-based precursors using laser [2–4], plasma [3], or thermolytic techniques [4]. For the latter technique, temperature regimes on the order of 600–1000° C are most common, with a few recent reports citing lower temperatures using halogenated precursors [5–7], or through alkali-metal catalyzed transformation of bulk carbon allotropes [8,9]. Sailor etal. have reported the first growth of non-amorphous carbon deposits at room temperature [10]. However, their electrochemical synthesis did not produce nanostructural carbon; due to the absence of nanosized catalytic seeds, the diameters of their fibers were > 5μm, and contained copious amounts of Cl, H, N, and O impurities.

Reaction of adamantylmagnesium bromide, AdaMgBr (Ada=C 10 H 15 ) with aluminum(III) chloride, gallium(III) chloride, dimethylgallium chloride, or dimethylaluminum chloride gives [Mg 3 BrCl 3 (OEt)(OEt 2 ) 6 ][Ada 3 AlBr] ( I ), [Mg 3 Br 2 Cl 3 (OEt 2 ) 6 ][Ada 2 GaBr 2 ] ( II ), [Mg 3 Br 4 (OEt)(OEt 2 ) 6 ][Ada 2 GaMe 2 ] ( III ), and [Mg 3 Br 4 (OEt)(OEt 2 ) 6 ][Ada 2 AlMe 2 ] ( IV ), respectively. These ionic compounds, characterized by 1 H- and 13 C-NMR, elemental analyses, and single crystal X-ray diffraction, contain trimetallic magnesium cations with each alkaline earth metal residing in a distorted octahedral environment. The aluminum and gallium atoms in the adamantyl-based anions reside in distorted tetrahedral environments. These substances are the first examples of adamantyl-based Group 13 organometallic compounds.

Tris(pentamethylphenyl)gallium, (Me5C6)3Ga, was prepared by reaction of pentamethylphenylmagnesium bromide with gallium(III) chloride in diethyl ether. The title compound, characterized by 1H and 13C NMR, elemental analyses, and single crystal X-ray diffraction, crystallizes in the P 1 (No. 2) space group with a=9.003(9) A, b=10.713(1) A, c=16.066(2) A, α=107.63 (3)°, β=97.63 (3)°, γ=90.08(3)°, for Z=2. Refinement converged at R1=0.050, wR2=0.11. The pentamethylphenyl ligands are configured about the gallium center in a propeller fashion at angles of 67.3°, 62.3°, and 60.9°.

The synthesis and molecular structures of tris(pentamethylphenyl)aluminum, (C6Me5)3Al, (I), and the magnesium cluster [Mg6(μ3-OH)2(μ3-Br)2(μ2-Br)8(OEt2)8] (II), are reported. Both compounds were isolated from the same system. The aluminum atom in (I) resides in an almost idealized trigonal planar environment. The dihedral angles of the pentamethylphenyl rings relative to the AlC3plane in (I) are 67.2, 62.4, and 61.2°. The neutral magnesium cluster, (II), is interesting in that contains six magnesium atoms each of which resides in octahedral environments.

In the title compound, [Ga(C12H18N2O2)Cl], the Ga atom is coordinated to a Cl atom and the two imine N and two enolate O atoms of the Schiff base ligand. The literature reveals few examples of a five-coordinate GaO2N2Cl environment, and only two where both the N and the O atoms are contained within the same ligand. This configuration has the effect of constraining the complex into a square-pyramidal geometry with less distortion than if formed by two or more ligands. The Ga—N and Ga—O distances are within the ranges expected for Ga–Schiff base derivatives. This compound is also the first group 13 complex containing the N,N′-ethyl­ene­bis­(acetyl­acetoneimine) (acacen) ligand.

Reaction of 1,4-dilithiotetraphenylbutadiene with phosphorus(III) bromide affords bis(tetraphenylbutadienyl)diphosphine, (Ph4C4)P–P(C4Ph4), with a phosphorus–phosphorus bond length of 2.2051(11) A.

Though the diversity of applications involving supercritical fluids (SCFs) continue to mount in virtually every sector of the scientific workplace, this environmentally-friendly medium is only briefly mentioned in undergraduate curricula; most often without hands-on laboratory experience. A new experimental module featuring this technology was introduced into an undergraduate inorganic chemistry laboratory. Nanoparticles of copper and aluminum oxide were formed using a variety of novel procedures, with scanning electron microscopy (SEM–EDS) and transmission electron microscopy (TEM) utilized for characterization. While particles of aluminum oxide were found to average 100 nm with sufficient aggregation, the copper nanoparticles were much smaller in diameter, with less agglomeration. A discussion of overall student sentiment and pedagogical outcomes from this module is also provided.