Rudy L. Luck

[NiL]3[BTC]2·14H2O [L=3,10-bis(2-ethyl)-1,3,5,8,10,12-hexaazacyclotetradecane, BTC=1,3,5-benzenetricarboxylate]: synthesis, structure and unique selective guest molecule absorption properties

Reaction of 1,3,5-benzenetricarboxylate with a macrocyclic Ni(II) complex leads to a porous metal-organic framework, which displays a high selectivity for ethanol sorption.

New polynuclear compounds of iron(II) chloride with oxygen donor ligands Part I. Fe4Cl8(THF)6: synthesis and a single crystal X-ray structure determination

Abstract A new polynuclear compound of Fe(II) chloride with oxygen donor ligands has been isolated as a colorless crystalline solid, Fe4Cl8(THF)6 (1), by the reaction of FeCl3 and Fe in THF. 1 consists of centrosymmetric, tetranuclear molecules with two different types of Fe atoms, two (Fe(1) and Fe(1)′) in trigonal bipyramidal environments and the others (Fe(2) and Fe(2)′) in octahedral environments. Each trigonal bipyramidally coordinated iron atom is linked through doubly- and triply-shared chlorine atoms to an iron atom in an octahedral environment. The magnetic moment of 1, per iron atom, at room temperature is 5.40 BM, which is a reasonable value for high spin Fe2+. The Fe…Fe distances are 3.656(1) and 3.750(1) A for Fe(1)…Fe(2) and Fe(2)…Fe(2)′, respectively. The order of FeCl distances, Fe(μ3-Cl)>Fe(μ2-Cl)>FeClt is as expected. The FeClt distance is 2.244(1) ]A, the Fe(μ2-Cl) distances are 2.355(1)–2.488(2) A and the Fe(μ3-Cl) distances are 2.506(1)–2.737(1) A. The average FeO distance is 2.135(9) A. Crystallographic data: 1, triclinic, space group P 1 , a = 10.607(2), b = 10.993(3), c = 10.038(2) A, α = 111.84(3)°, β = 98.28(3)°, γ = 63.18(3) °, V = 969.2(6) A3, Z = 1, R = 0.048 (Rw = 0.069) for 188 parameters and 2616 unique data having Fo2>3σ(Fo2).

Synthesis, characterization and reactivity of MoCl2(O)(O2)(OPR3)2, OPR3=OPMePh2, OPPh3; an isomerization catalyst for some allylic alcohols

Abstract Adding one equivalent of H2O2 to compounds of stoichiometry MoCl2(O)2(OPR3)2, OPR3=OPMePh2 or OPPh3, leads to the formation of oxo–peroxo compounds MoCl2(O)(O2)(OPR3)2. The compound MoCl2(O)(O2)(OPMePh2)2 crystallized with an unequal disorder, 63%:37%, between the oxo and peroxo ligands and can be isolated in reasonable yields. MoCl2(O)(O2)(OPPh3)2 was not isolated in pure form, co-crystallized with MoCl2(O)2(OPPh3)2 in two ratios, 18%:82% and 12%:88%, respectively, and did not contain any disorder in the arrangement of the oxo and peroxo groups. These complexes accomplish the isomerization of various allylic alcohols at rates competitive to that reported for CH3ReO3.

Controlled Knoevenagel reactions of methyl groups of 1,3,5,7-tetramethyl BODIPY dyes for unique BODIPY dyes

Formyl groups at 6- and 2,6-positions initiated Knoevenagel reactions of the methyl groups at the 7, and 1,7-positions of 1,3,5,7-tetramethyl BODIPY dyes with aromatic aldehydes. Formation of vinyl bonds at the 7-, and 1,7-positions facilitates further Knoevenagel reactions of the methyl groups at the 3,5-positions. This approach offers fast, facile and versatile ways to prepare potential novel building blocks of BODIPY dyes for conjugated oligomers, dendrimers, and highly water-soluble, near-infrared emissive sensing materials.

Interlocking frameworks. A consequence of enlarging spacers from 4-pyridinecarboxylate to 4-(4-pyridyl)benzoate

Abstract The crystallinity of evacuated framework polymer {[Cu(pyca)]·2H2O}α, pyca=4-pyridinecarboxylate, is preserved after removal of the interstitial solvent molecules. Staying with Cu2+ and enlarging the spacers from 4-pyridinecarboxylate to 4-(4-pyridyl)benzoate results in a sixfold interpenetrating diamondoid framework. This is composed of different extended arrays in a 4:2 ratio each individually composed of one of two geometric isomers of Cu (distorted octahedral and square pyramidal) found in the crystal.

Mechanistic Studies of CC Bond Cleavage of Nitriles by Dinuclear Metal Cryptates

We previously reported that dinuclear copper(II) cryptate [Cu(2)L](4+) cleaves the C-C bond of acetonitrile at room temperature to produce a cyano-bridged dinuclear cryptate and methanol, whereby the reaction mechanism has not yet become clear. We have now systemically investigated this reaction, and four cryptates, [Cu(2)L](ClO(4))(4) (1), [Zn(2)L](ClO(4))(4) (2), [Cu(2)L(H(2)O)(2)](CF(3)SO(3))(4) (5), and [Cu(2)L(OH)(OH(2))](ClO(4))(3) (6) are reported here. Cryptates 1 and 2 can cleave the C--C bonds of acetonitrile, propionitrile, and benzonitrile at room temperature under open atmospheric conditions to give cyano-bridged cryptates [Cu(2)L(CN)](ClO(4))(3) (3) and [Zn(2)L(CN)](ClO(4))(3) (4), respectively, and the corresponding alcohol. In contrast, 5 and 6 do not show any C-C bond activation of nitriles, as the interior axial positions of Cu(II) in 5 and 6 are occupied by water/OH(-). The C-C bond cleavage of (S)-(+)-2-methylbutyronitrile by 2 produced (R)-(-)-2-butanol only; that is, the cleavage reaction proceeds through an S(N)2 pathway (Walden inversion).

Packing and compositional disorder with MoO2Cl2(OPMePh2)2, MoOCl3(OPMePh2)2 and MoCl4(OPMePh2)2 as assessed by single crystal X-ray diffraction

The structures as determined by single crystal X-ray determinations of MoO 2 Cl 2 (OPMePh 2 ) 2 and various mixtures of MoO 2 Cl 2 (OPMePh 2 ) 2 ( A ), MoOCl 3 (OPMePh 2 ) 2 ( B ) and MoCl 4 (OPMePh 2 ) 2 ( C ) specifically in ratios 40.2/59.8; 30.8/69.2; 14/86; 4/96 in A / B , 100% B and 82/18 in B / C are reported. The structural data illustrate that both compositional and packing disorder afford mechanisms by which apparent long and different MoO bond distances can be obtained.

Sorption and coprecipitation of trace concentrations of thorium with various minerals under conditions simulating an acid uranium mill effluent environment

Abstract Sorption of thorium by pre-existing crystals of anglesite (PbSO4), apatite (Ca5(PO4)3(HO)), barite (BaSO4), bentonite (Na0.7Al3.3Mg0.7Si8O20(OH)4), celestite (SrSO4), fluorite (CaF2), galena (PbS), gypsum (CaSO4·2H2O), hematite (Fe2O3), jarosite (KFe3(SO4)2(OH)6), kaolinite (Al2O3·2SiO2·2H2O), quartz (SiO2) and sodium feldspar (NaAlSi3O8) was studied under conditions that simulate an acidic uranium mill effluent environment. Up to 100% removal of trace quantitiees of thorim (approx. 1.00 ppm in 0.01 N H2SO4) from solution occurred within 3 h with fluorite and within 48 h in the case of bentonite. Quartz, jarosite, hematite, sodium feldspar, gypsum and galena removed less than 15% of the thorium from solution. In the coprecipitation studies, barite, anglesite, gypsum and celestite were formed in the presence of thorium (approx. 1.00 ppm). Approximately all of the thorium present in solution coprecipitated with barite and celestite; 95% coprecipitated with anglesite and less than 5% with gypsum under similar conditions. When jarosite was precipitated in the presence of thorium, a significant amount of thorium (78%) was incorporated in the precipitate.

Molecular architecture via coordination and multi-intermolecular interactions: Synthesis, structures and magnetic properties of one-dimensional coordination polymers of macrocyclic nickel(II) complexes with terephthalate and trans-butene dicarboxylate

Reactions of terephthalate (TP 2 - ) and trans-butene dicarboxylate (BDC 2 - ) with macrocyclic complexes [NiL 1 ](ClO 4 ) 2 , [NiL 2 ](ClO 4 ) 2 , [NiL 3 (ClO 4 ) 2 and [NiL 4 ](ClO 4 ) 2 which contain different pendant groups gave five new one-dimensional coordination polymers with the formula [NiL 1 (TP)] n (1), [NiL 2 (TP)] n (2), [NiL 1 (BDC)] n (3), [NiL 3 (BDC)] n (4) and [NiL 4 (BDC)] n (5), respectively (L 1 = 3,10-bis(2-phenethyl)-1,3,5,8,10,12-hexaazacyclo-tetradecane, L 2 = 3,10-bis(2-benzyl)-1,3,5,8,10,12-hexaazacyclo-tetradecane, L 3 = 3,10-bis(2-ethyl)-1,3,5,8,10,12-hexaazacyclo-tetradecane, L 4 = 3,10-bis(2-hydroxyethyl)-1,3,5,8,10,12-hexaazacyclo-tetradecane). These compounds were characterized by single-crystal X-ray analyses. All structures are made up of one-dimensional chains of [NiL 1 , 2 , 3 , 4 ] 2 + units with TP 2 - /BDC 2 - anions. Each Ni(II) ion in the chain is six-coordinated with four nitrogen atoms from the macrocyclic ligand in the equatorial plane, and two carboxylate oxygen atoms from the TP 2 - or BDC 2 - group in axial position. In the structures, different intermolecular interactions and packing modes between the 1D chains are found depending on the nature of the pendant groups and the bridging ligands. The ID chains tend to interact via π...π (compound 1) or C-H...π (compounds 2 and 3) interactions when the compounds contain benzene rings as pendant groups or as bridging ligands, otherwise the ID chains tend to interact via hydrogen bonding interactions (4 and 5). In 1-4, the ID chains are aligned in a parallel mode. In 5, the 1D chains are arranged in a crossover mode. Magnetic susceptibility measurements indicate that these compounds show weak ferromagnetic interactions between the nearest Ni(II) ions through the TP 2 - or BCD 2 - bridges.

Circularly polarized luminescence and structural studies of a dysprosium(III) complex with an octadentate macrocyclic ligand bearing benzylphosphinate groups

The solution and solid-state structures of a Dy(III) complex with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetryltetramethylenetetra(benzylphosphinate) have been examined by means of circularly polarized luminescence spectroscopy and crystallographic methods. The spectroscopic measurements show that the complex occurs in solution as enantiomeric pairs that do not racemize on the luminescence time-scale. It is also demonstrated that the complex crystallizes in two different unit cells, even though no significant intramolecular differences in the arrangement of the ligand around the central Dy(III) ion were evident.