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Polymorphism and an unexpected reconstructive phase transition in [Cu(trop)(μ-OMe)]2 (trop = tropolonate) were studied by single crystal and powder X-ray diffraction; the phase transition is associated with a huge hysteresis of ca. 200 °C. In the readily reproducible crystal form, the methoxide-bridged dinuclear subunits aggregate to infinite chains by longer bonds in the Jahn-Teller distorted coordination sphere. Analogous alkoxide-bridged derivatives with the substituted ligand hinokitiol (hino), [Cu(hino)(μ-O R)]2 ( R = Me, Et, iPr) form pairs of dinuclear complexes and aggregate to discrete tetranuclear molecules. The inter-cation distance patterns are reflected in the magnetic properties of these two structure types: Strong antiferromagnetic coupling within the dinuclear subunits is observed in either case, but susceptibility measurements confirm differences in exchange coupling between neighboring central CuII atoms. [ABSTRACT FROM AUTHOR]

A complex featuring a terminal magnesium hydride bond supported by an NNNN macrocyclic ligand, [Mg{Me3TACD ⋅Al( iBu)3}H] ( 3), was formed from its labile Al( iBu)3 adduct. Use of Al( iBu)3 to block the amido nitrogen of the NNNN macrocyclic ligand was essential to prevent aggregation. The structurally characterized compound 3 reacted with BH3 to give the BH4 derivative, whereas Me3SiCCH and PhSiH3 led to the corresponding acetylide and silyl derivative under H2 elimination. Pyridine is inserted into the MgH bond to give selectively the 1,4-dihydropyridinate. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [Cu(ClO4)2(C4H12N2)2], (I), is reported at 100, 250 and 400 K. The CuII cation in this complex is coordinated in a distorted octahedral mode characteristic of Jahn-Teller systems. The coordination of the perchlorate ligands via longer, and presumably weaker, axial Cu-O distances varies significantly as a function of temperature. One of the Cu-O distances increases between 100 and 250 K, and one of the Cu-O-Cl angles expands between 250 and 400 K. At all temperatures, the complex forms a two-dimensional N-H...O hydrogen-bond network in the (001) plane. [ABSTRACT FROM AUTHOR]

Large magnesium hydride aggregates [Mg13(Me3TACD)6(μ2-H12)(μ3-H6)][A]2 ((Me3TACD)H=1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane; A=AlEt4, Al nBu4, B{3,5-(CF3)2C6H3}4) were synthesized stepwise from alkyl complexes [Mg2(Me3TACD)R3] (R=Et, nBu) and phenylsilane in the presence of additional MgII ions. The central magnesium atom is octahedrally coordinated by six hydrides as in solid α-MgH2 of the rutile type. Further coordination to six magnesium atoms leads to a substructure of seven edge-sharing octahedra as found in the hexagonal layer of brucite (Mg(OH)2). Upon protonolysis in the presence of 1,2-dimethoxyethane (DME), this cluster was degraded into a tetranuclear dication [Mg2(Me3TACD)(μ-H)2(DME)]2[A]2. [ABSTRACT FROM AUTHOR]

Große Magnesiumhydrid ‐ Aggregate [Mg13(Me3TACD)6(μ2 ‐ H12)(μ3 ‐ H6)][A]2 ((Me3TACD)H=1,4,7 ‐ Trimethyl ‐ 1,4,7,10 ‐ tetraazacyclododecan; A=AlEt4, AlnBu4, B{3,5 ‐ (CF3)2C6H3}4) wurden schrittweise aus Alkylkomplexen [Mg2(Me3TACD)R3] (R=Et, nBu) und Phenylsilan in Gegenwart von zusätzlichen MgII ‐ Ionen synthetisiert. Das zentrale Magnesiumatom ist wie in festem α ‐ MgH2 vom Rutil ‐ Typ oktaedrisch von sechs Hydriden koordiniert. Weitere Koordination zu sechs Magnesiumatomen führt zu einer Unterstruktur mit sieben eckenverknüpften Oktaedern, ähnlich einer hexagonalen Schicht von Brucit (Mg(OH)2). Durch Protonolyse in Gegenwart von 1,2 ‐ Dimethoxyethan (DME) wurde dieser Cluster zu dem vierkernigen Dikation [Mg2(Me3TACD)(μ ‐ H)2(DME)]2[A]2 abgebaut. Leicht & groß: Ein ausgedehnter Magnesiumhydrid ‐ Cluster mit [Mg13H18] ‐ Kern wird durch einen NNNN ‐ Liganden stabilisiert (Mg grün, N blau, H weiß). Die Struktur des zentralen [Mg7H12]2+ ‐ Fragments leitet sich formal von Mg(OH)2 (Brucit) ab und unterscheidet sich daher stark von derjenigen des salzartigen MgH2. [ABSTRACT FROM AUTHOR]