Two Blatter Radicals Face-to-Face: A Constrained Diradical Architecture.

Cofacial arrangement of two Blatter radicals enforced by the -naphthalene scaffold represents a new approach to stable diradicals with strong through-space interactions. Two stereoisomers of the naphthalene-diradicals, and , are investigated by XRD, VT-EPR, UV-vis, electrochemical, kinetic, and DFT methods. In solutions, both stereoisomers exist as open-shell singlets with Δ = -3.

[-BH-1-CN-10-Azinium] Anions: Photoactive Heteroditopic Ligands for Metal Complexes.

A new class of rigid, photoactive heteroditopic anionic ligands based on the 1,10-disubstituted [-BH] anion was designed and six of these compounds were obtained from [-BH] in three steps with yields in the range of 25-30%. The design includes two apical substituents, a metal coordinating cyano group and an azinium (4-cyanopyridinium, 4,4'-bipyridinium, pyrazinium, pyrimidinium, and pyridazinium), which provides a secondary binding site. The azinium substituent is involved in an efficient intramolecular charge transfer process and compensates one of the two delocalized negative charges of the boron cluster.

Production of low-sulfur fuels from catalytic pyrolysis of waste tires using formulated red mud catalyst.

Waste tires (WT) are produced in millions of tons per annum and their safe disposal is always a major environmental challenge because of fire hazards and the increasing cost of landfills. WT has high organic matter content that can be converted into fuels and chemicals if suitable technologies can be developed. Herein we report the catalytic pyrolysis of WT using formulated red mud catalyst to produce low sulfur fuel that can be fractionated or can be used without fractionation.

[-BH-10-PhI-1-COOH] Anion: An Intermediate for Functional Anionic Carboxylate Ligands.

A potentially general intermediate, [-BH-10-PhI-1-COOH], for a class of functional anionic carboxylic acids, [-BH-10-X-1-COOH], was obtained in four steps and 26% overall yield from [-BH]. It was converted to the pyridinium derivative (X = CHN) and subsequently to coordination complexes with (phen)Cu and (phen)Zn ions. Both the acid and Zn(II) complex exhibit a cage-to-pyridine charge-transfer band.

Physical structure of constitutional isomers influences antiproliferation activity of thiosemicarbazone-alkylthiocarbamate copper complexes.

A series of hybrid thiosemicarbazone-alkylthiocarbamate copper complexes with similar electronic environments but distinct physical structures have been prepared, characterized, and evaluated for antiproliferation activity. The complexes include the constitutional isomers (1-phenylpropane-1-imine-(O-ethylthiocarbamato)-2-one-(N-methylthiosemicarbazonato))copper(II) (CuL) and (1-phenylpropane-1-one-(N-methylthiosemicarbazonato)-2-imine-(O-ethylthiocarbamato))copper(II) (CuL) along with (1-propane-1-imine-(O-ethylthiocarbamato)-2-one-(N-methylthiosemicarbazonato))copper(II) (CuL). Complexes CuL and CuL differ in the positions of the pendent thiosemicarbazone (TSC) and alkylthiocarbamate (ATC) moieties on the 1-phenylpropane backbone.

[-BH-1,10-(COOH)]: a building block for functional materials?

[-BH-1,10-(COOH)] was obtained in five steps and 40% overall yield from [-BH]. It can be converted to [-BH-1,10-(CO)] and subsequently to carbonium ylides [-BH-1-COOH-10-(C(NRCH))]. The diacid, its derivatives, and di-ylide [-BH-1,10-(C(NHMe))] are characterized by spectroscopic and single crystal XRD methods augmented with DFT results.

Effect of Stacking Interactions on the Translation of Structurally Related Bis(thiosemicarbazonato)nickel(II) HER Catalysts to Modified Electrode Surfaces.

A series of crystalline nickel(II) complexes (-) based on inexpensive bis(thiosemicarbazone) ligands diacetylbis(4-methyl-3-thiosemicarbazone) (HATSM), diacetylbis(4,4-dimethyl-3-thiosemicarbazone) (HATSDM), and diacetylbis[4-(2,2,2-trifluoroethyl)-3-thiosemicarbazone] (HATSM-F) were synthesized and characterized by single-crystal X-ray diffraction and NMR, UV-visible, and Fourier transform infrared spectroscopies. Modified electrodes - were prepared with films of - deposited on glassy carbon and evaluated as potential hydrogen evolution reaction (HER) catalysts. HER studies in 0.

Photocatalytic hydrogen evolution on Si photocathodes modified with bis(thiosemicarbazonato)nickel(ii)/Nafion.

The molecular catalyst diacetyl-bis(N-4-methyl-3-thiosemi-carbazonato)nickel(ii) (NiATSM) was integrated with Si for light-driven hydrogen evolution from water. Compared to an equivalent loading of Ni metal, the NiATSM/p-Si electrode performed better. Durability of the surface-bound catalyst under operation in acid was achieved without covalent attachment by using Nafion binding.

Dicyanometalates as Building Blocks for Multinuclear Iron(II) Spin-Crossover Complexes.

A synthetic strategy featuring dicyanometalates [M(CN)] (M = Ag, Au) as N-coordinating ditopic linkers connecting partially blocked Fe centers has been employed to produce heterometallic hexanuclear complexes, which exhibit spin-crossover (SCO) behavior at the Fe sites. The reaction between tris(2-pyridylmethyl)amine (tpma)-capped Fe ions and [Ag(CN)] proceeded with partial decomposition of the dicyanoargentate and led to the formation of {[Fe(tpma)](μ-CN)[μ-Ag(CN)]}(ClO)·3HO (), in which both [Ag(CN)] and CN act as bridging ligands, and the opposite [Ag(CN)] bridges are engaged in a pronounced argentophilic d-d interaction. In an analogous synthesis, the more stable [Au(CN)] species remained intact and furnished the complex {[Fe(tpma)][μ-Au(CN)]} (), which features two Fe centers bridged by two [Au(CN)] dimers.

Spin Crossover in Fe(II) Complexes with N4S2 Coordination.

Reactions of Fe(II) precursors with the tetradentate ligand S,S'-bis(2-pyridylmethyl)-1,2-thioethane (bpte) and monodentate NCE(-) coligands afforded mononuclear complexes [Fe(bpte)(NCE)2] (1, E = S; 2, E = Se; 3, E = BH3) that exhibit temperature-induced spin crossover (SCO). As the ligand field strength increases from NCS(-) to NCSe(-) to NCBH3(-), the SCO shifts to higher temperatures. Complex 1 exhibits only a partial (15%) conversion from the high-spin (HS) to the low-spin (LS) state, with an onset around 100 K.

Spin crossover in tetranuclear Fe(II) complexes, {[(tpma)Fe(μ-CN)]4}X4 (X = ClO4(-), BF4(-)).

Two Fe(II) complexes, {[(tpma)Fe(μ-CN)]4}X4 (X = ClO4(-) (1a), BF4(-) (1b); tpma = tris(2-pyridylmethyl)amine), were prepared by reacting the {Fe(tpma)}(2+) building block with (Bu4N)CN. The crystal structures of 1a and 1b feature a tetranuclear cation composed of cyanide-bridged Fe(II) ions, each capped with a tetradentate tpma ligand. The Fe4(μ-CN)4 core of the complex is strongly distorted, assuming a butterfly-like geometry.

Fluorinated copper(I) carboxylates as advanced tunable p-dopants for organic light-emitting diodes.

Volatile copper(I) benzoates with variable degrees of fluorination are used for p-doping of organic hole-transport layers in single-carrier devices, charge-generation layers, and in organic light-emitting diodes. The charge-transport abilities of the doped materials correlate with the degree and position of the fluorination on the aromatic ring of the carboxylate groups.

Building a two-dimensional network from mixed-valence copper units held together by acetone bridges.

The mixed-valence supramolecular product di-μ2-acetone-di-μ3-trifluoroacetato-deca-μ2-trifluoroacetato-octacopper(I)dicopper(II), [Cu10(C2F3O2)12(C3H6O)2] or {[Cu(I)4(O2CCF3)4]2-{μ2-OC(CH3)2}2-[Cu(II)2(O2CCF3)4]}, was prepared by co-deposition of two building units, namely a bis-acetone adduct of [Cu(II)2(O2CCF3)4] and a very electrophilic tetranuclear [Cu(I)4(O2CCF3)4] complex. The asymmetric unit contains one molecule of the compound with a total of ten independent Cu atoms. Acetone molecules serve as bridges between the [Cu(II)2(O2CCF3)4] and [Cu(I)4(O2CCF3)4] units.

Tetra-ethyl-ammonium dicyanido(5,10,15,20-tetra-phenyl-porphyrinato)ferrate(III) di-chloro-methane monosolvate.

The title compound, (C8H20N)[Fe(C44H28N4)(CN)2]·CH2Cl2 or (Et4N)[Fe(TPP)(CN)2], was recrystallized from di-chloro-methane-diethyl ether. The compound crystallizes with the two unique halves of the Fe(III) porphyrinato complex, one tetra-ethyl-ammonium cation and one inter-stitial di-chloro-methane mol-ecule within the asymmetric unit. Both anionic Fe(III) complexes exhibit inversion symmetry.

Tetranuclear copper(I) carboxylates: the effect of a stepwise increase in Lewis acidity on solid-state structures and photoluminescence.

X-Ray diffraction studies of three aliphatic copper(I) carboxylates revealed a tetranuclear core structure for [Cu(4)(O(2)CCH(2)CH(3))(4)] (1), [Cu(4)(O(2)CCF(3))(O(2)CCH(2)CH(3))(3)] (2), and [Cu(4)(O(2)CCF(2)CF(3))(4)] (3). The effect of a stepwise increase in electrophilicity on solid-state interactions of copper(I) tetramers as well as the implications of structural variations on photoluminescent properties of the above copper(I) propionates have been discussed.

Insulated copper(I) "wires": structural variations and photoluminescence.

An unprecedented "molecular wire" type of structure for the copper(I) carboxylate family has been synthesized by utilizing copper-copper interactions and controllable switch of copper-oxygen interactions. Several modifications of the same complex, copper(I) 2,4,6-triisopropylbenzoate, have been isolated to allow evaluation of the structural variation effects on photoluminescent behavior.

Reversible Cu(4) <--> Cu(6) core interconversion and temperature induced single-crystal-to-single-crystal phase transition for copper(I) carboxylate.

The first example of a reversible [Cu(4)] <--> [Cu(6)] interconversion for polynuclear copper(I) complexes under controlled experimental settings is reported. It illustrates the key role of specific crystal growth conditions for accessing the target cluster nuclearity that consequently determines physical properties of the resulting solid state products. Thus, when copper(I) benzoate crystallizes from a 1,2-dichlorobenzene solution at room temperature, it forms [Cu(4)]-core based crystalline material, [Cu(4)(O(2)CC(6)H(5))(4)] (1).

Tetranuclear copper(I) clusters: impact of bridging carboxylate ligands on solid state structure and photoluminescence.

The X-ray crystallographic characterization and solid state photoluminescence (PL) study of three new tetranuclear copper(I) clusters, [Cu4(O2CR)4], R = (3-F)C6H4 (1), (2,3,4-F)3C6H2 (2), and CF3/C6F5 (3), revealed a dependence of PL on the structural type.