Through this review we can follow the various phases that have led to the discovery of the new allotrope form of silicon: silicene. This is a one-atom thick silicon sheet arranged in a honeycomb lattice, similar to graphene. For silicon, which usually is sp(3) hybridized, it represents an unusual and ...

The lower rim functionalized hexahomotrioxacalix[3]arene derivatives cone- and cone- bearing three benzyl and three N,N-diethyl-2-aminoethoxy groups, respectively, were synthesized from triol . Their complexation with 2-(3,4-dihydroxyphenyl)ethylamine (dopamine), 5-hydroxytryptamine (serotonin), and 2-phenylethylamine (phenethylamine), which have biologically important activities, has been studied by (1)H-NMR spectroscopy. The chemical shifts of the aromatic protons ...

The calix[4]arene secondary-amide derivative L was synthesized, and its complexation with alkali-metal cations in acetonitrile (MeCN) was studied by means of spectrophotometric, NMR, conductometric, and microcalorimetric titrations at 25 °C. The stability constants of the 1:1 (metal/ligand) complexes determined by different methods were in excellent agreement. For the complexation of ...

The title thia-calix[4]arene derivative, C(36)H(34)Br(2)O(8)S(4), adopts an unusual pinched cone conformation with the prop-oxy-substituted benzene rings inclined inward [forming a dihedral angle of 33.4 (1)°] and with the brominated benzene rings bent outward, making a dihedral angle of 66.1 (1)°. In the crystal, the mol-ecules form chains along [001] via C-H⋯S hydrogen ...

Easy come, easy go: The first molecular SO(2) complexes of the lanthanides (Ln=Sm, Eu) are prepared. The compounds can reversibly coordinate gaseous SO(2) . Concomitant with the addition and removal of SO(2) , the color of the complexes changes reversibly. The structures of the SO(2) compounds could be confirmed in ...

We found that the alignments of the alkali cations can be controlled by a distortion of Prussian blue framework; the rubidium ions form a rod structure in a distorted framework of Rb(0.85)Cu[Fe(CN)(6)](0.95)·1.3H(2)O, while the cesium ions are isolated dot structures in a non-distorted framework of Cs(0.97)Cu[Fe(CN)(6)](0.99)·1.1H(2)O. The Madelung energy calculations ...

Orientation- and position-controlled synthesis of single-crystal topological insulator (Bi2Se3 and Bi2Te3) nanoplate array was achieved on mica substrates using van der Waals epitaxy. Individual ultrathin nanoplates with the lateral dimension up to ~0.1 mm or uniform thickness down to 1~2 nm were produced. Single-Dirac-cone surface states of nanoplate aggregates were ...

The structural and spectroscopic changes in complexes of FCCKrH[ellipsis (horizontal)]Y and FKrCCH[ellipsis (horizontal)]Y (Y = BF, CO, N(2), OH(2), OH(CH(3)), O(CH(3))(2)) were computed at the MP2∕6-31++G(d,p) level of theory and compared with the corresponding properties for FCCH[ellipsis (horizontal)]Y. The computed bond length changes and frequency shifts on complexation were rationalized ...

A new door is open! Foldamers have been successfully utilized for the development of a molecular device. Termed foldaxanes by analogy with rotaxanes, these structures are formed through a multitude of noncovalent interactions between double-helical foldamers and rod-shaped guest molecules. The foldaxanes move in a screw-type motion and open up ...

Calix[4]arene derivatives, blocked in the cone conformation and functionalized with two to four guanidinium units at the upper rim were synthesized and investigated as catalysts in the cleavage of the RNA model compound 2-hydroxypropyl p-nitrophenyl phosphate. When compared with the behavior of a monofunctional model compound, the catalytic superiority of ...

We theoretically propose and investigate a TM-polarized one-dimensional photonic crystal nanocavity with a horizontal SiO₂ slot on a suspended silicon nanobeam via the three-dimensional finite-element method. The ultrahigh quality factor and ultrasmall effective mode volume of 1.5×10⁷ and 0.176 half-wavelength cubic of the horizontally SiO₂-slotted nanocavity show strong possibilities for ...

In the title compund, C(21)H(33)PSe, the Se=P bond is part of a distorted tetra-hedral environment on the P atom. Both cyclo-hexyl groups adopt chair conformations. A cone angle of 170° was calculated using an adaptation of the Tolman model. Inter-molecular C-H⋯Se and C-H⋯Cg contacts are observed (Cg is the centroid ...

Here we demonstrate a facile approach to grow uniform and large area single layer graphene directly over polycrystalline metal foil from fullerene, where fullerene molecules formed rod-like polycrystals in the toluene solvent. The generated pressure on sandwich structures has enhanced the density (scalable) as well as quality of graphene at ...

The excited-state deuteron transfer (ESDT) of deuterated 7-hydroxyquinoline (7DQ) along a heterogeneous hydrogen (H)-bonded chain composed of two deuterated alcohol (ROD) molecules having different acidities, as a model system of a proton wire consisting of diverse amino acids, has been investigated. To understand dynamic differences between deuteron transfer and proton ...

By using urea as the new nitrogen source, for the first time, Sc-based metal nitride clusterfullerenes (NCFs), Sc(3) N@C(2n) (2n=80, 78, 70, 68), have been synthesized successfully. The optimum molar ratio of Sc(2) O(3) /CO(NH(2) )(2) /C for the synthesis of Sc NCFs is 1:3:15. The yield of Sc(3) N@C(80) ...

This randomized, double-blind, 12 h clinical study tested the effect of a single brushing with two Zn-containing toothpastes on volatile sulfur compound (VSC) levels in morning breath. The following toothpastes were each tested by all 28 participants: A-Zn toothpaste, B--experimental toothpaste (Zn citrate + PVM/MA copolymer) and C--control toothpaste without ...

The methyltransferases BT_2972 and BVU_3255 from two different Bacteroides species that are antibiotic-resistant pathogens from the human intestine were cloned, overexpressed and purified, yielding approximately 120 mg of each protein from 1 l culture. Apo BT_2972 and BVU_3255 and their complexes with S-adenosylmethionine or S-adenosylhomocysteine were crystallized in four different crystal forms using ...

The purpose of this work is to investigate the effect of genipin/hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex on the intestinal absorption of genipin and identify its mechanism of action. The phase solubility profile was classified as AL-type, indicating the formulation of 1:1 stoichiometry inclusion complex. Fourier transform infrared spectroscopy, Differential scanning calorimetry, ...

The gas phase structures of epibatidine, one of the most potent agonists of nicotinic acetylcholine receptors (nAChRs), are determined by means of infrared multiphoton dissociation (IRMPD) spectroscopy and quantum chemistry calculations. Comparison of the experimental and theoretical spectra provides evidence that about 15% of epibatidine is protonated on the Nsp(2) ...

Measurements are presented of the current-voltage (I-V) characteristics of individual thiol-tethered porphyrin molecules (isolated in an alkanethiol matrix) and of self-assembled monolayers. In both cases, it is found that I/V(2) displays a minimum at a characteristic "transition voltage" V(m). Repeated measurements of the transition voltage enable both its time development ...

A more flexible nucleotide building block for the synthesis of new DNA based porphyrin-zipper arrays is described. Changing the rigid acetylene linker between the porphyrin substituent and the 2'-deoxyuridine to a more flexible propargyl amide containing linkage leads in part to an increased duplex stability. The CD spectra reveal different ...

Cobalt complexes of N-confused porphyrins and benziphthalocyanine, which both feature organometallic bonds at the macrocycle cores, catalyze the cyclopropanation of styrene with a higher trans-selectivity than the corresponding porphyrin and phthalocyanine complexes.

The reaction between H(2)O(2) and a pyridine-coordinated ferric porphyrin encapsulated by a cyclodextrin dimer yielded a hydroperoxoferric porphyrin intermediate, PFe(III)-OOH, which rapidly decomposed to oxoferryl porphyrin (PFe(IV)═O). Upon reaction with H(2)O(2), PFe(IV)═O reverted to PFe(III)-OOH, which was converted to carbon monoxide-coordinated ferrous porphyrin under a CO atmosphere. PFe(IV)═O in the ...

In order to investigate the mechanism of the N-H migration in asymmetrical metal-free porphyrins, four porphyrins of electron-withdrawing or electron-donating substituent at the β-position were studied theoretically. For porphyrin 2 (R = OMe), 3 (R = Me), and 4 (R = NO(2)), four different asynchronous N-H migration pathways exist due ...

Reactions of a saddle-distorted Mo(V)-porphyrin complex, [Mo(DPP)(O)(H(2)O)]ClO(4) (1·ClO(4); DPP(2-) = dodecaphenylporphyrin dianion), with tetra-n-butylammonium (TBA) salts of Keggin-type heteropolyoxomatalates (POMs), α-[XW(12)O(40)](n-) (X = P, n = 3, 2; X = Si, n = 4, 3; X = B, n = 5; 4), in ethyl acetate/acetonitrile gave 2:1 complexes formulated as ...

Creation of higher-ordered polymeric architectures composed of alternative assemblies of single-walled carbon nanotubes (SWNTs) and fibrous porphyrin J-aggregates can be easily achieved utilizing the cationic semi-artificial polysaccharide which can act not only as a tubular host for SWNTs but also as a one-dimensional template for porphyrin molecules. This new class ...

A bridged bis(β-cyclodextrin) 3 with a tetrathiafulvalene (TTF) linker was synthesized by an electrophilic reaction of mono-6-deoxy-6-iodo-β-cyclodextrin 1 with 6,7-bis(methylsulfanyl)-2,3- bis(2-cycanoethylsulfanyl)tetrathiafulvalene 2 under the alkaline condition. Benefiting from the good solubilizing ability of the β-cyclodextrin unit, the solubility limit of 3 in water could reach 1.0 × 10(-3) M, i.e. ...

A porphyrin nanobarrel, 1, that can encapsulate C(60) effectively was prepared via a concise coupling route. The structures of both 1 and C(60)@1 were confirmed by single-crystal X-ray diffraction analysis.

The vertical excitation energies of H(2)TPP [TPP = 5,10,15,20-tetraphenylporphyrin(2-)], H(2)FcPh(3)P [FcPh(3)P = 5-ferrocenyl-10,15,20-triphenylporphyrin(2-)], cis-H(2)Fc(2)Ph(2)P [cis-Fc(2)Ph(2)P = 5,10-bisferrocenyl-15,20-diphenylporphyrin (2-)], trans-H(2)Fc(2)Ph(2)P [trans-Fc(2)Ph(2)P = 5,15-bisferrocenyl-10,20-diphenylporphyrin(2-)], H(2)Fc(3)PhP [H(2)Fc(3)PhP = 5,10,15-trisferrocenyl-20-phenylporphyrin(2-)], and H(2)TFcP [TFcP = 5,10,15,20-tetraferrocenylporphyrin(2-)] were investigated using a time-dependent density functional theory (DFT) approach and compared to their experimental UV-vis spectra in the ...

Porphyrin-based synthetic receptors containing urea, carbamate, or amide groups were designed and synthesized for carbohydrate recognition. The receptors have equatorially and convergently directed hydrogen-bonding sites into which the urea, carbamate, or amide groups were introduced above the porphyrin plane. The receptors exhibited remarkable affinities to pyranoside/furanoside derivatives in organic media, ...

meso-Alkylidene (m-benzi)pentaphyrin containing exocyclic C=C double bonds at two meso-positions is synthesized and fully characterized for the first time. The single crystal X-ray crystallographic analysis shows a concave conformation with two pyrrole rings inverted. The first protonation occurs exclusively at core nitrogen. The synthesized compound displays concentration dependent chromogenic responses ...

The effects of complexation--by bidentate nitrogen-containing ligands such as pyrazine and 4,4'-bipyridine commonly used for porphyrin self-assembly--on the photophysics of the model metalloporphyrin, ZnTPP, are reported. Ligation to form the 5-coordinate species introduces an intramolecular charge transfer (ITC) state that, depending on the oxidation and reduction potentials of the electron ...

Three novel mixed (phthalocyaninato)(porphyrinato) yttrium double-decker complexes appended with one metal-free porphyrin chromophore at the para, meta, and ortho position, respectively, of one meso-phenyl group of the porphyrin ligand in the double-decker unit through ester linkage, 3-5, have been designed, synthesized, and spectroscopically characterized. The photophysical properties of these three ...

Defined face-to-face structures of phthalocyanine and porphyrin chromophores can be prepared using a modular strategy that allows directional, stepwise construction. μ-Oxo linkage between the central group of 14 metalloid atoms Si and Ge ensures π-overlap between the macrocycles, and exciton coupling effects further extend the absorption profile to provide arrays ...

Among three noble-metal-free molecular devices (1-3) containing a porphyrin photosensitizer and a cobaloxime catalyst, the one with a zinc porphyrin unit displayed apparently higher efficiency for photoinduced H(2) production than complex 2 with a magnesium porphyrin and 3 with a free-base porphyrin, possibly due to the formation of a TEAZnPor-Co ...

Reaction of hydrido[5,10,15,20-tetrakis(p-tolyl)porphyrinato]iridium(III) (Ir(ttp)H) (1) with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) (2) at room temperature gave a 90% yield of the unsupported iridium(II) porphyrin dimer, Ir(II)(2)(ttp)(2) (3). Kinetic measurements revealed that the oxidation followed overall second-order kinetics: rate = k[Ir(ttp)H][TEMPO], k(25 °C) = 6.65 × 10(-4) M(-1). The entropy of activation (ΔS(‡) = ...

A series of π-extended phosphorescent palladium(II) and platinum(II) porphyrin complexes were synthesized, in which additional benzene rings are fused radially onto at least one of the four peripheral benzo groups. The photophysical properties of the metalloporphyrins palladium(II)-meso-tetra-(4-fluorophenyl)mononaphthotribenzoporphyrin (Pd1NF), cis-palladium(II)-meso-tetra-(4-fluorophenyl)dibenzodinaphthoporphyrin (Pd2NF), and palladium(II)-meso-tetra-(4-fluorophenyl)monobenzotrinaphthoporphyrin (Pd3NF) and the corresponding platinum(II) compounds (Pt1NF, cis-Pt2NF, ...

Bis(pyridine)[meso-tetrakis(heptafluoropropyl)porphyrinato]iron(III), [Fe(THFPrP)Py(2)](+), was reported to be the low-spin complex that adopts the purest (d(xz), d(yz))(4)(d(xy))(1) ground state where the energy gap between the iron d(xy) and d(π)(d(xz), d(yz)) orbitals is larger than the corresponding energy gaps of any other complexes reported previously (Moore, K. T.; Fletcher, J. T.; Therien, M. ...

The diprotonated form of a fluorinated free base porphyrin, namely 5-(p-aminophenyl)-10,15,20-tris(pentafluorophenyl)porphyrin (H(2)FAP), can catalyze the reduction of oxygen by a weak electron donor, namely ferrocene (Fc). At a water/1,2-dichloroethane interface, the interfacial formation of H(4)FAP(2+) is observed by UV-vis spectroscopy and ion-transfer voltammetry, due to the double protonation of H(2)FAP ...

Zinc-porphyrin-appended norbornene derivative 6, the corresponding dimer 7, coherently aligned single-stranded polynorbornene 5, and zinc-porphyrin-linked double-stranded polymeric ladderphane 3 have been used for complexation with 1,4-diazabicyclo[2.2.2]octane (DABCO) to generate an array of porphyrin-DABCO supramolecular scaffolds. The stoichiometries of the complex formation are analyzed in detail by (1) H NMR spectroscopy as ...

The synthesis and characterization of a new type of bisporphyrin system is reported where the two macrocycles are linked in a cofacial arrangement by a substituted carbazole bridge. The three nitrogen atoms of the carbazole bridge in the compounds may complex a metal ion and thus provide a new parameter ...

Naphthobipyrrole is a potentially useful building block for porphyrin and porphyrin analogue synthesis. Reported here is a simple, generalizable synthetic route to α-formylated, β-substituted naphthobipyrroles and their use in the preparation of binaphthoporphycenes. The resulting binaphthoporphycenes possess a planar geometry as determined via a single-crystal X-ray diffraction analysis; they also ...

A novel two-step bottom-up approach to construct a 2D long-range ordered, covalently bonded fullerene/porphyrin binary nanostructure is presented: in the first place, reversible supramolecular interactions between C60 and 5,15-bis(4-aminophenyl)-10,20-diphenylporphyrin are exploited to obtain large domains of an ordered binary network, subsequently a reaction between fullerene molecules and the amino-groups residing ...

Interaction of meso-tetra(4-sulfonatophenyl)porphyrin (H2tppS4) with weak and strong protic acid have been studied by UV-vis spectroscopy in water, dichloromethane and methanol. Different shifts of the Soret and Q(0,0) bands in the three solvents, the aggregation of diprotonated species and the stability of porphyrin-acid adducts in the solution, may be explained ...

Meso-tetrasubstituted Mg(II) porphyrins containing six membered phenyl groups (MgTPP) and five membered thienyl (MgTThP) and furyl groups (MgTFP) were synthesized and structurally characterized, and the effects of meso-substituents on electronic properties were studied using NMR, absorption, fluorescence spectroscopy, and electrochemical studies. Density functional theory (DFT) calculations were carried out to ...

To examine the influence of fullerene on the macrocyclic ring conformation, crystal structures of a series of cocrystals of 2,3,5,10,12,13,15,20-octaphenylporphyrin, M(TPP)(Ph)(4) (M = 2H, Co(II), Cu(II)), and 2,312,13-tetramethyl-5,7,8,10,15,17,18,20-octaphenyl-porphinato copper(II), CuTPP(Ph)(4)(CH(3))(4), derivatives with fullerene, C(60), were elucidated. Furthermore, crystal structures of the parent porphyrins, M(TPP)(Ph)(4) (M = Co(II), Cu(II)) complexes, were ...

A rhenium(I) complex of an N-heterocyclic carbene ligand embedded in an N-confused porphyrin core was serendipitously synthesized by the reaction of an inner-methylated N-confused porphyrin with Re(2)(CO)(10).

N-Annulated perylene fused porphyrins 1 and 2 were synthesized by oxidative dehydrogenation using a Sc(OTf)(3)/DDQ system. These newly synthesized hybrid molecules are highly soluble in organic solvents and exhibit remarkably intense near-IR absorption, as well as detectable photoluminescence quantum yields, all of which are comparable to or even exceed those ...

Seven different porphyrin compounds have been investigated as colorimetric gas sensors for a wide range of volatile organic compounds. The porphyrins examined were the free base and Mg, Sn, Zn, Au, Co, and Mn derivatives of 5,10,15,20-tetrakis[3,4-bis(2-ethylhexyloxy)phenyl]-21H,23H-porphine. Chloroform solutions of these materials were prepared and changes in their absorption spectra ...

The reaction of the doubly oxidized beta-octaisobutyl-meso-tetraphenylporphyrin (OiBTPP, 4), which has a 16 pi-electronic structure at the porphyrin core, with a variety of metal reagents was investigated. The reaction of 4 with SnCl(2) followed by ethanolysis afforded an 18 pi-electron tin complex, (OiBTPP)Sn(OEt)(2) (5), in a redox manner. No reactions ...