Synthesis and charge-transfer dynamics in a ferrocene-containing organoboryl aza-BODIPY donor-acceptor triad with boron as the hub.

A N,N'-bis(ferroceneacetylene)boryl complex of 3,3'-diphenylazadiisoindolylmethene was synthesized by the reaction of an N,N'-difluoroboryl complex of 3,3'-diphenylazadiisoindolylmethene and ferroceneacetylene magnesium bromide. The novel diiron complex was characterized by a variety of spectroscopic techniques, electrochemistry, and ultrafast time-resolved methods. Spectroscopy and redox behavior was correlated with the density functional theory (DFT) and time-dependent DFT calculations.

Redox and photoinduced electron-transfer properties in short distance organoboryl ferrocene-subphthalocyanine dyads.

Reaction between ferrocene lithium or ethynylferrocene magnesium bromide and (chloro)boronsubphthalocyanine leads to formation of ferrocene- (2) and ethynylferrocene- (3) containing subphthalocyanine dyads with a direct organometallic B-C bond. New donor-acceptor dyads were characterized using UV-vis and magnetic circular dichroism (MCD) spectroscopies, NMR method, and X-ray crystallography. Redox potentials of the rigid donor-acceptor dyads 2 and 3 were studied using the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) approaches and compared to the parent subphthalocyanine 1 and conformationally flexible subphthalocyanine ferrocenenylmethoxide (4) and ferrocenyl carboxylate (5) dyads reported earlier.

Electrochemistry and catalytic properties for dioxygen reduction using ferrocene-substituted cobalt porphyrins.

Cobalt porphyrins having 0-4 meso-substituted ferrocenyl groups were synthesized and examined as to their electrochemical properties in N,N'-dimethylformamide (DMF) containing 0.1 M tetra-n-butylammonium perchlorate as a supporting electrolyte. The examined compounds are represented as (Fc)n(CH3Ph)(4-n)PorCo, where Por is a dianion of the substituted porphyrin, Fc and CH3Ph represent ferrocenyl and/or p-CH3C6H4 groups linked at the four meso-positions of the macrocycle, and n varies from 0 to 4.

Hydroxo-bridged dicopper(II,III) and -(III,III) complexes: models for putative intermediates in oxidation catalysis.

A macrocyclic ligand (L(4-)) comprising two pyridine(dicarboxamide) donors was used to target reactive copper species relevant to proposed intermediates in catalytic hydrocarbon oxidations by particulate methane monooxygenase and heterogeneous zeolite systems. Treatment of LH4 with base and Cu(OAc)2·H2O yielded (Me4N)2[L2Cu4(μ4-O)] (1) or (Me4N)[LCu2(μ-OH)] (2), depending on conditions. Complex 2 was found to undergo two reversible 1-electron oxidations via cyclic voltammetry and low-temperature chemical reactions.

Synthesis, characterization, and electron-transfer processes in indium ferrocenyl-containing porphyrins and their fullerene adducts.

Three new indium(III) tetra- and penta(ferrocenyl)-substituted porphyrins of the general formula XInTFcP [X = Cl(-), OH(-), or Fc(-); TFcP = 5,10,15,20-tetraferrocenylporphyrin(2-); Fc = ferrocene] have been prepared and characterized by UV-vis, magnetic circular dichroism (MCD), (1)H, (13)C, 2D, and variable-temperature NMR spectroscopy, as well as elemental analysis. Molecular structures of the ClInTFcP, FcInTFcP, and FcInTFcP@4C60 complexes were determined by X-ray crystallography with the last compound being not only the first example of a C60 adduct to the organometallic porphyrins but also the first structure in which organometallic porphyrin antennas intercalated into four electron-transfer channels. The electronic structures and relative energies of individual atropisomers, as well as prospective electron-transfer properties of fullerene adducts of XInTFcP complexes, were investigated by the Density Functional Theory (DFT) approach.

Dithiolopyranthione Synthesis, Spectroscopy and an Unusual Reactivity with DDQ.

The bicyclic pyran thiolone tetrahydro-3αH-[1,3]dithiolo[4,5-β]pyran-2-thione () engages in a highly unusual fragmentation in the presence of DDQ. The pyran thiolone, , was synthesized by chlorination of 3,4-dihydro-2H-pyran (), followed by condensing with CS and NaSH. Reaction of with DDQ generates the isomerized pyran thiolone tetrahydro-3αH-[1,3]dithiolo[4,5-β]pyran-2-thione () and 4-benzyl-5-(3-hydroxypropyl)-1,3-dithiole-2-thione () via a deep-seated rearrangement.

Cadmium(II) chloride, bromide and iodide complexes with 4,4'-bipyridazine: when are diazine and halide bridges (in)compatible?

In poly[di-μ-chlorido-μ-(4,4'-bipyridazine)-κ(2)N(1):N(1')-cadmium(II)], [CdCl(2)(C(8)H(6)N(4))](n), (I), and its isomorphous bromide analogue, [CdBr(2)(C(8)H(6)N(4))](n), (II), the halide atom lies on a mirror plane and the Cd(II) ion resides at the intersection of two perpendicular mirror planes with m2m site symmetry. The pyridazine rings of the ligand lie in a mirror plane and are related to each other by a second mirror plane perpendicular to the first. The compounds adopt the characteristic structure of the [M(II)X(2)(bipy)] type (bipy is bipyridine) based on crosslinking of [Cd(μ-X)(2)](n) chains [Cd-Cl = 2.

Comparative electronic structures and UV-vis spectra of tribenzosubporphyrin, tribenzomonoazasubporphyrin, tribenzodiazasubporphyrin, and subphthalocyanine: insight from DFT and TDDFT calculations.

Electronic structures, geometries, and vertical excitation energies of chloroboron subphthalocyanine, tribenzodiazasubporphyrin, tribenzomonoazasubporphyrin, and tribenzosubporphyrin were calculated using density functional theory (DFT) and time-dependent (TD) DFT coupled with polarized continuum model (PCM) approach. Molecular geometries calculated at the BP86/6-311G(d) level reveal bowl-shape, trigonal prismatic conformations for all compounds with a variable bowl-depth that depends on the number of meso-nitrogen atoms in corresponding molecule. TDDFT-PCM calculations predict that the Q-band should undergo gradual high-energy shift, while the B-band should undergo low-energy shift upon stepwise substitution of the meso-nitrogen atoms in subphthalocyanine toward tribenzosubporphyrin.

Photoinduced charge transfer in short-distance ferrocenylsubphthalocyanine dyads.

Two new ferrocenylsubphthalocyanine dyads with ferrocenylmethoxide (2) and ferrocenecarboxylate (3) substituents directly attached to the subphthalocyanine ligand via the axial position have been prepared and characterized using NMR, UV-vis, and magnetic circular dichroism (MCD) spectroscopies as well as X-ray crystallography. The redox properties of the ferrocenyl-containing dyads 2 and 3 were investigated using the cyclic voltammetry (CV) approach and compared to those of the parent subphthalocyanine 1. CV data reveal that the first reversible oxidation is ferrocene-centered, while the second oxidation and the first reduction are localized on the subphthalocyanine ligand.

Facile access to a series of large polycondensed pyridazines and their utility for the supramolecular synthesis of coordination polymers.

Domino cyclization of ketoenols and hydrazine leads to a series of polycondensed pyridazines, which reveal potential as rigid N-donor multidentate ligands for supramolecular synthesis of open coordination polymers.

Unexpected fluorescence properties in an axially sigma-bonded ferrocenyl-containing porphyrin.

Molecular structure, redox, and unexpected fluorescence properties of a tetraphenylporphyrin tin(iv) complex axially sigma-bonded with two ferrocene substituents were investigated using UV-vis, MCD, electro- and spectroelectrochemical methods as well as DFT calculations and X-ray crystallography.

1,2,4,5-tetrazine: an unprecedented micro4-coordination that enhances ability for anion pi interactions.

A series of framework coordination polymers reveals the use of 1,2,4,5-tetrazines as efficient bridging ligands towards silver(i) and copper(i) ions. All four nitrogen atoms were functional as lone pair donors leading to an unprecedented mu(4)-coordination of the ligands (1,2,4,5-tetrazine, ttz; 3,6-dimethyl-1,2,4,5-tetrazine, Me(2)ttz) in [Ag(ttz)(X)] (X = NO(3), ; ClO(4), ), [Ag(2)(Me(2)ttz)(NO(3))(2)] (), [Ag(2)(Me(2)ttz)(H(2)O)(2)(ClO(4))(2)] (), [Ag(3)(Me(2)ttz)(H(2)O)(2)(CF(3)SO(3))(3)] () and [Cu(4)Cl(4)(Me(2)ttz)] (). In and , micro(4)-tetrazines and silver ions (AgN(4), Ag-N 2.

Copper(II) bromide and copper(II) acetate complexes of 4,4'-(p-phenylene)bipyridazine.

4,4'-(p-Phenylene)bipyridazine, C(14)H(10)N(4), (I), and the coordination compounds catena-poly[[dibromidocopper(II)]-mu-4,4'-(p-phenylene)bipyridazine-kappa(2)N(2):N(2')], [CuBr(2)(C(14)H(10)N(4))](n), (II), and catena-poly[[[tetrakis(mu-acetato-kappa(2)O:O')dicopper(II)]-mu-4,4'-(p-phenylene)bipyridazine-kappa(2)N(1):N(1')] chloroform disolvate], {[Cu(2)(C(2)H(3)O(2))(4)(C(14)H(10)N(4))].2CHCl(3)}(n), (III), contain a new extended bitopic ligand. The combination of the p-phenylene spacer and the electron-deficient pyridazine rings precludes C-H.

Hydrate frameworks involving the pyridazino[4,5-d]pyridazine unit as a multiple hydrogen-bond acceptor.

1,4,5,8-Tetramethylpyridazino[4,5-d]pyridazine trihydrate, C(10)H(12)N(4) x 3 H(2)O, (I), and 1,2,3,6,7,8-hexahydrocinnolino[5,4,3-cde]cinnoline tetrahydrate, C(12)H(12)N(4) x 4 H(2)O, (II), exhibit exceptional functionality of the condensed N(4)-heteroaromatic frame as a symmetric acceptor of four hydrogen bonds [N...

Silver(I) ions bridged by pyridazine: doubling the ligand functionality for the design of unusual 3D coordination frameworks.

Nitrogen donor tetradentate ligands 4,4'-bipyridazine (bpdz) and pyridazino[4,5-d]pyridazine (pp) were prepared by inverse electron demand Diels-Alder cycloaddition reactions of 1,2,4,5-tetrazine. Examination of their behaviour towards silver(I) ions revealed a special potential of the ligands for the design of 3D coordination frameworks involving characteristic polynuclear and polymeric silver(I)-pyridazine motifs and multiple coordination of the ligands. Ag4(pp)5(ClO4)4 and Ag4(pp)5(SiF6)(BF4)(2).

4,4'-Bipyridazine: a new twist for the synthesis of coordination polymers.

A new polydentate ligand 4,4'-bipyridazine (4,4'-bpdz) was prepared by employing inverse electron demand cycloaddition of 1,2,4,5-tetrazine. A unique combination of structural simplicity, ampolydentate character and efficient donor properties towards Cu(I), Cu(II) and Zn(II) provide wide new possibilities for the synthesis of coordination polymers incorporating the 4,4'-bpdz module either as a bi-, tri- or tetradentate connector between the metal ions. 1D coordination polymers Cu(2)(4,4'-bpdz)(CH(3)CO(2))(4) x 4H(2)O and Zn(4,4'-bpdz)(NO(3))(2), and interpenetrated (4,4)-nets in [Cu(4,4'-bpdz)(2)(H(2)O)(2)]S(2)O(6) were closely related to 4,4'-bipyridine compounds.

Silver(I) sulfate coordination polymers with 4,4'-bipyridazine and pyridazino[4,5-d]pyridazine.

Poly[[micro(4)-4,4'-bipyridazine-micro(5)-sulfato-disilver(I)] monohydrate], [[Ag(2)(SO(4))(C(8)H(6)N(4))].H(2)O](n), (I), and poly[[aqua-micro(4)-pyridazino[4,5-d]pyridazine-micro(3)-sulfato-disilver(I)] monohydrate], [[Ag(2)(SO(4))(C(6)H(4)N(4))(H(2)O)].H(2)O](n), (II), possess three- and two-dimensional polymeric structures, respectively, supported by N-tetradentate coordination of the organic ligands [Ag-N = 2.

Metal-organic frameworks exhibiting strong anion-pi interactions.

Coordination polymers offer a significant potential for applications in adsorption, guest and anion recognition and sensing. Their structure commonly provides binding sites for such specific interactions as pi-pi stacking and XH..

Cadmium nitrate coordination polymers with substituted pyridazino[4,5-d]pyridazines.

catena-Poly[[aquabis(nitrato-kappa2O,O')cadmium(II)]-mu-1,2,3,6,7,8-hexahydrocinnolino[5,4,3-cde]cinnoline-kappaN1:kappaN6], [Cd(NO3)2(C12H12N4)(H2O)]n, (I), and catena-poly[[[bis(nitrato-kappa2O,O')cadmium(II)]-mu-2,2,7,7-tetramethyl-1,2,3,6,7,8-hexahydrocinnolino[5,4,3-cde]cinnoline-kappaN1:kappaN6] chloroform solvate], {[Cd(NO2)2(C12H12N4)].CHCl3}n, (II), are the first structurally examined cadmium-pyridazine coordination compounds. They possess one-dimensional polymeric structures supported by the bidentate bridging function of the cinnolino[5,4,3-cde]cinnoline ligands, which lie about inversion centres.

Fused pyridazines: rigid multidentates for designing and fine-tuning the structure of hybrid organic/inorganic frameworks.

Fused pyridazines (1,2,3,6,7,8-hexahydro-cinnolino[5,4,3-cde]cinnoline, L and its 2,2,7,7-tetramethyl derivative, Me4L) are designed as rigid multidentate ligands for the construction of framework solids. In combination with copper(I) bromide (iodide) they provide excellent structural examples for predictive engineering and the possibilities for further fine-tuning of the framework architectures facilitated by the tetradentate function of the ligands and effective cooperation of organic and inorganic bridges. This study features control over helical structures for (CuX)n chains and homo/heterochiral combination of the helices in the lattice, the design of a range of channelled and tubular CuX networks and the structural significance of ligand shape complementarity.

Self-assembly sodalite-like framework.

The dense packing of shape complementary N-donor molecules dominates the self-assembly of coordination polymers possessing sodalite-like topology and supports nanosize molecular cages.