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Funding: This research was funded by JSPS KAKENHI through a Grant-in-Aid for Scientific Research (C), grant number JP18K05262. Photoluminescentliquid crystals (PLLCs) have attracted significant attention owing to their broad applicabilityin thermosensing and PL switching. Extensive efforts have been madeto develop bistolane-based PLLCs containing flexible units at both molecular terminals, and it has been revealed that their PL behavior can switch with the phase transition between the crystallineand LC phases. Although slight modulation of the flexible unit structure dramatically alters the LC and PL behaviors, few studies into modification of the flexible units have been conducted. With the aim of achieving dynamic changes in their physical behaviors, we developed a family of bistolane derivatives containing a simple alkyl or a fluoroalkyl flexible chain, and carried out a detailed systematic evaluationof their physical behaviors. Bistolanes containing a simple alkyl chain showed a nematic LC phase, whereas switching the flexible chain in the bistolane to a fluoroalkyl moiety significantly altered the phase to generate a smectic phase. The fluoroalkyl-containing bistolanes displayed a stronger deep blue PL than their corresponding non-fluorinated counterparts, even in the crystalline phase, which was attributed to the construction of rigid molecular aggregates through intermolecular F···H and F···F interactions to suppress non-radiative deactivation. Publisher PDF

The degradation of Nitrilotriacetic Acid (NTA), which results from the oxidation of hydroxyl radicals formed in the process, is a major deficiency in the present Fe-NTA system for the oxidation of hydrogen sulfide to sulfur by air. The degradation of NTA can be slowed down considerably by the addition of a hydroxyl radical scavenger. In this study, a series of inorganic and organic materials was tested as scavengers/inhibitors of hydroxyl radicals in attempts to improve the Fe-NTA system. The results showed that N-methylpyrrolidinone and ethylene glycol could be used as potentially powerful scavengers of hydroxyl radicals to improve the Fe-NTA system.

Reaction of PhPCl2 with pamoic acid in a 2:1 molar ratio gives a bisphosphinite 5 as a conformational mixture of 5a and 5b which show different solubility in THF and Et2O. The less soluble biaxial conformer 5a was isolated spectrally pure, while it is very difficult to get pure biequatorial 5b without contamination of 5a. Oxidation of 5a with hydrogen peroxide/elemental sulfur or selenium gave the corresponding chalcogenides. The conformational features of the compounds were revealed by X-ray crystallography. In addition, two examples of complexes of 5a were prepared, the chelate complex [PtCl2{(5a)-P, P′}] and the bis-rhodium bridging complex from [RhCl2Cp*]2 dimer.

Six phosphorus-containing analogues of nitrilotriacetic acid (NTA) or ethylenedinitrilotetraacetic acid (EDTA) form stable Fe(III) complexes which have been tested as catalysts for the oxidation of hydrogen sulfide. Ligand 4, phosphonomethyliminodiacetic acid (NTAP), was found to be comparable with NTA in efficiency of catalytic activity such as the conversion of hydrogen sulfide to sulfur, half-life of ligand, consumption of ligand per kg of sulfur product. A quantitative analytical method of phosphorus-containing ligand in the absorbed solution has been successfully established by applying 31P-{1H} NMR.

Two aminomethylphosphane derivatives of adenine 9-(2-{bis[(diphenylphosphanyl)methyl]amino}ethyl)adenine (La) and 9-(3-{bis[(diphenylphosphanyl)methyl]amino}propyl)adenine (Lb) were synthesised. Oxidation of La and Lb with H2O2, elemental sulfur or elemental selenium led to the corresponding oxidized products 4a/b−6a/b. Both La and Lb behave as didentate ligands towards late transition metals. Reaction of La or Lb with [MX2(cod)] (M = Pd, Pt; X = Cl, Me) gave chelate complexes 7a/b−10a/b. Reaction of La or Lb with [AuCl(tht)] or [{RuCl(μ-Cl)(p-MeC6H4iPr)}2] gave the didentate bridging complexes 11a/b and 12a. All compounds have been fully characterised by microanalysis, IR, 1H and 31P{1H} NMR spectroscopy, and EI/CI/FAB mass spectrometry. 1H{31P} NMR and 1H-13C correlation experiments were used to confirm the spectral assignments where necessary. Two compounds were structurally characterised by X-ray crystallographic analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Condensation of Ph2PCH2OH with 2-(diphenylphosphanyl)aniline in toluene gave the new unsymmetrical ligand Ph2PCH2NHC6H4PPh2 (1) in good yield. Oxidation of 1 with H2O2 or elemental sulfur led to the oxidised products Ph2P(O)CH2NHC6H4P(O)Ph2 (2) and Ph2P(S)CH2NHC6H4P(S)Ph2 (3). The new ligand 1 demonstrates three distinct modes of coordination. Reaction of compound 1 with [MX2(cod)] (M = Pd, Pt; X = Cl, Br, Me) or [Mo(CO)4(pip)2] gave the chelate complexes [PdCl2(Ph2PCH2NHC6H4PPh2-PX,PA)] (4), [PdBr2(Ph2PCH2NHC6H4PPh2-PX,PA)] (5), [PtCl2(Ph2PCH2NHC6H4PPh2-PX,PA)] (6), [PtMe2(Ph2PCH2NHC6H4PPh2-PX,PA)] (7) and [Mo(CO)4(Ph2PCH2NHC6H4PPh2-PX,PA)] (8). Coordination of 1 with [{RuCl(μ-Cl)(η3:η3-C10H16)}2] or [{RhCl(μ-Cl)(η5-C5Me5)}2] gave the monodentate complexes [RuCl2(η3:η3-C10H16)(Ph2PCH2NHC6H4PPh2-PX)] (9) and [RhCl2(η5-C5Me5)(Ph2PCH2NHC6H4PPh2-PX)] (10). Reaction of 1 with [{IrCl(μ-Cl)(η5-C5Me5)}2] led to a mixture from which the monodentate complex [IrCl2(η5-C5Me5)(Ph2PCH2NHC6H4PPh2-PX)] (11) and the chelate cationic complex [IrCl(η5-C5Me5)(Ph2PCH2NHC6H4PPh2-PX,PA)][Cl] (12) were separated. Abstraction of the chloride ligands from complexes 9 and 10 with AgClO4 gave the cationic chelate complexes [RuCl(η3:η3-C10H16)(Ph2PCH2NHC6H4PPh2-PX,PA)][ClO4] (13) and [RhCl(η5-C5Me5)(Ph2PCH2NHC6H4PPh2-PX,PA][ClO4] (14). Compound 1 also functions as a bridging ligand when reacted with two molar equivalents of [AuCl(tht)] or one molar equivalent of [{RhCl(μ-Cl)(η5-C5Me5)}2] to give the bimetallic complexes [Ph2P{AuCl}CH2NHC6H4PPh2{AuCl}] (15) and [{RhCl2(η5-C5Me5)}2(Ph2PCH2NHC6H4PPh2)] (16). The dioxidised compounds 2 and 3 and several typical complexes 8, 9, 11 and 14 were structurally characterised by X-ray diffraction. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Amines react with DMF-NO2 adduct under nonaqueous condition to give solid aryl diazonium nitrate in high purity and excellent yield.

The viscosities of aqueous sodium alginate solutions were measured in different NaCl concentrations (Cs) at 298 K. Based on the Odijk–Skolnick–Fixman theories, the electrostatic persistence lengths were calculated for various ionic strengths. The intrinsic persistence length of sodium alginate in solution was determined to be 125 A by the method suggested by Odijk. In the region of , the increase in intrinsic viscosity, [η], for sodium alginate on decreasing the Cs is due to the larger contribution of electrostatic persistence length to the total persistence length, and the departure of [η]calc from [η]expl is attributed to the variation of the Flory Φ constant with ionic strength. A peak was observed in the plot of reduced viscosity v. sodium alginate concentration at a constant low ionic strength. As in the treatment of Rinaudo et al., this maximum in reduced viscosity is attributed to a preferential intermolecular distance. The roles of electrostatic persistence length, the critical inter-rod spacing and the effect of added salt concentration on this maximum are discussed. Copyright © 2001 John Wiley & Sons, Ltd.

The M/G ratio, dyad and triad frequencies in the sodium alginate chain, were determined from 13C-nmr spectra. The interactions of sodium alginate in solution with the univalent cations K+ ion and Na+ ion have been investigated by viscometry and membrane osmometry. The dependencies of intrinsic viscosity, Huggins constant, and second virial coefficient on ionic strength were observed, and the maximums in reduced viscosity were obtained in low KCl and NaCl concentrations, respectively. These show that the electroviscous effects play an important role in polyelectrolyte solution, and the effect of the Na+ ion on aqueous solution of sodium alginate is greater than the K+ ion. The experimental observations are interpreted in terms of ion-pair formation with carboxyl groups of mannuronate and isolated guluronate residues and cooperation “egg-box” binding between polyguluronate chain sequence. The difference of interaction between univalent cations and alginate chains in solution is attributed to the ability of their binding with the polyion, which depends on the properties of ions itself. © 1998 John Wiley & Sons, Inc. Biopoly 46: 395–402, 1998

The viscosity behaviour of alginate-Cu2+-NaCl systems has been experimentally examined at various concentrations of cupric and sodium salts. Dependence of the intrinsic viscosity of alginate as a function of NaCl concentration is discussed to supplement the previous study which shows a similar behaviour to that found for other polyelectrolytes in aqueous solution in the presence of an added salt. The effects of sodium ions on the cupric association in cupric-induced alginate solutions were investigated by means of viscosity measurements. The mechanisms of complex formation in the presence of the simple added salt were studied. It was found that, at a given NaCl concentration, the viscosity of the mixture will pass through a maximum with increasing cupric concentration. The amounts of cupric cations corresponding to the maximum depends on the concentration of NaCl in the solution. Comparison of salt effects on the viscosity behaviour of alginate solutions during sol—gel transition reveals that an optimum NaCl concentration of 10−2 mol 1−1 exists where the viscosity of the mixture gives a maximum value at a certain cupric amount. This result indicates that salt effects play an important role in the sol—gel transition of the polyelectrolyte solutions. The observed phenomenon was interpreted in terms of conformational change of polyelectrolyte chain due to the addition of salt resulting in a different cross-linking mode in the system.

The interaction mode between cupric ions and alginate in aqueous solutions during sol–gel transition has been experimentally examined at different temperatures. Some clusters were found to pass through a conformational transformation as the temperature increased, i.e. clusters formed by intramolecular crosslinks turned into intermolecular crosslinking clusters. This transformation of the interaction mode is not reversible as the temperature decreases. The interaction mode between cupric ions and alginate was re-examined by optical absorption techniques, and results suggest that the coordination of cupric ions mainly occurs to carboxyl groups and that the stoichiometric ratio f is proportional to the fraction of crosslinks formed. © 1997 John Wiley & Sons, Ltd.

The reaction of 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4- diselenide (Woollins' Reagent, WR) with phenylalkyl-cyanamides (RR'NC N, R = PhCH2CH2, R' = CH3 and R = PhCH2CH2CH2, R' = H) in refluxing toluene led to novel heterocyclic selenazadiphospholaminediselenides 1 and 2 (43% and 42% yields), the latter being hydrolyzed to the unusual zwitterionic carbamidoyl(phenyl) phosphinodiselenoic acids 3 and 4 in excellent yields (96% and 98%). Postprint

A series of Fe(III) salts and organic solvents have been screened to develop novel non-aqueous catalysts for the conversion of H2S to sulfur. FeCl3/95% N-methylpyrrolidinone/5% H2O was found to be a most efficient non-aqueous system. The process chemistry, the proposed mechanism of catalytic oxidation of H2S, and the electrochemistry are discussed.

Reaction of Ph2PCl with alanine methyl ester affords the chiral aminophosphine Ph2NHCH(CH3)C(O)OCH3 (dppal) which reacts with M(COD)Cl2 to give Pt(dppal)2Cl2 (1) and Cl(dppal)PdCl2Pd(dppal)Cl (2). The X-ray structures of dppalO, 1 and 2 are reported. The amino acid containing ligand forms intramolecular H bonds with the C–O–C or CO oxygen atoms within the ligand and with the cis chlorides in the complexes.

N-diphenylphosphinoamino methyl/ethyl esters, dppam, react with [PtCl2(cod)] and [RhCl(cod)]2 to give cis-[PtCl2(dppam-P)2] and [RhCl(cod)(dppam-P], while interaction of dppam with [PdCl2(cod)] leads to different complexes.

Two aminophosphine derivatives of adenine N9-(N2′-diphenylphosphinoaminoethyl)adenine L1 and N9-(N2′-diphenylphosphino-N2′-n-propylaminoethyl)adenine L2 were synthesized. Oxidation of L1 and L2 with H2O2, elemental sulfur or elemental selenium led to the corresponding oxidized products 5–10. Both L1 and L2 behave as monodentate ligands towards late transition metals. Reaction of compound L1 or L2 with [AuCl(tht)], [{RhCl(μ-Cl)(η5-C5Me5)}2], [{IrCl(μ-Cl)(η5-C5Me5)}2], [{Rh(μ-Cl)(cod)}2], [{RuCl(μ-Cl)(η3:η3-C10H16)}2] and [{RuCl(μ-Cl)(p-MeC6H4iPr)}2] gave the corresponding “dangling” monodentate complexes 11–20, leaving the adenine ring free for complementary hydrogen bonding. Interaction of L1 and L2 with [MX2(cod)] (M = Pt; X = Cl, Me) in 2 : 1 molar ratio also gave monodentate complexes 21 and 22. All compounds have been fully characterized by microanalysis, IR, 31P-{1H} NMR, 1H NMR and EI/CI/FAB MS spectroscopies. 1H-{31P} NMR, 1H–1H-COSY or 1H–13C correlation experiments were used to confirm the spectral assignments. Four compounds were structurally characterized by crystallographic X-ray analysis.