Two difluoroboron dipyrromethene (BODIPY) based fluorescent dyes - 4,4-difluoro-3-{2-[4-(dimethylamino)phenyl]ethenyl}-8-[4-(methoxycarbonyl)phenyl]-1,5,7-trimethyl-3a,4a-diaza-4-bora-s-indacene (1) and 4,4-difluoro-3-[2-(4-fluoro-3-hydroxyphenyl)ethenyl]-8-[4-(methoxycarbonyl)phenyl]-1,5,7-trimethyl-3a,4a-diaza-4-bora-s-indacene (3) - have been synthesized via condensation of p-N,N-dimethylaminobenzaldehyde and 4-fluoro-3-hydroxybenzaldehyde, respectively, with 4,4-difluoro-8-[4-(methoxycarbonyl)phenyl]-1,3,5,7-tetramethyl-3a,4a-diaza-4-bora-s-indacene (2). UV-vis spectrophotometry and steady-state and time-resolved fluorometry have been used to study the spectroscopic and photophysical characteristics of in various solvents. The multi-parameter Kamlet-Taft {pi*, alpha, beta} solvent scales and a new, generalized treatment of the solvent effect, proposed by Catalán (J. Phys. Chem. B, 2009, 113, 5951-5960), have been used in the analysis of the solvatochromic shifts of the UV-vis absorption and fluorescence emission maxima of 1-3, and the rate constants of excited-state deactivation via fluorescence (k(f)) and radiationless decay (k(nr)). The four Catalán solvent scales (dipolarity, polarizability, acidity and basicity of the medium) are the most appropriate for describing the solvatochromic effects. Solvent dipolarity and polarizability are the important causes for the solvatochromism of 1. Conversely, the absorption and emission maxima of 2 and 3 are hardly dependent on the solvent: the small changes reflect primarily the polarizability of the solvent surrounding the dye. Fluorescence decay profiles of 1 can be described by a single-exponential function in aprotic solvents, whereas two decay times are found in alcohols. The fluorescence decays of 2 (lifetimes tau in 1.9-2.9 ns range) and 3 (tau between 3.5 and 4.0 ns) are mono-exponential in all solvents studied. The fluorescence properties of dye are very sensitive to the solvent: upon increasing solvent dipolarity, the fluorescence quantum yields and k(f) values decrease and the emission maxima become more red-shifted. The k(f) values of 2 [(1.6 +/- 0.3) x 10(8) s(-1)] and 3 [(1.5 +/- 0.2) x 10(8) s(-1)] are practically independent of the solvent properties. The crystal structure of reveals that the BODIPY core is nearly planar with the boron atom moved out of the plane. The angle between the phenyl group at the meso-position and the BODIPY plane equals 80 degrees.
The new series of silver(I) coordination polymers [Ag(N-N)(μ-PTA)]n(X)n (1, 2, 4-8, 10, 11) and discrete monomers [Ag(N-N)(PTA)2](X) (3, 9) {N-N = bpy (1-3), dtbpy (4), neocup (5, 6), phen (7-9), dione (10, 11); X = NO3 (1, 3, 5, 7, 9, 10), PF6 (2, 4, 6, 8, 11)} were generated by self-assembly reactions, in MeOH at ~25 °C, of AgNO3 or AgPF6 with 1,3,5-triaza-7-phosphaadamantane (PTA) and the corresponding polypyridines, namely 2,2'-bipyridine (bpy), 4,4'-di-tert-butyl-2,2'-bipyridine (dtbpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (neocup) and 1,10-phenanthroline-5,6-dione (dione). The compounds were obtained as air and light stable solids and characterized by IR, (1)H and (31)P{(1)H} NMR spectroscopy, ESI(+)-MS and elemental analyses. The crystal structure of 1 was determined by single crystal X-ray diffraction analysis, revealing infinite one-dimensional (1D) linear chains driven by μ-PTA N,P-linkers. Apart from representing the first examples of the metal-PTA derivatives bearing polypyridine ligands, 1-11 also feature solubility in water (S(25°C) ≈ 4-18 mg mL(-1)). Selected compounds (1, 3, 5, 7, 9 and 10) were thus tested for their biological properties and found to exhibit significant antibacterial and antifungal activities, screened in vitro against the standard strains of Staphylococcus aureus, Staphylococcus pyogenes, Staphylococcus pneumoniae, Staphylococcus sanguinis, Staphylococcus mutans, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Furthermore, the compounds 5, 7, 9 and 10 show a pronounced antiproliferative activity against human malignant melanoma (A375), and the effects on the inhibition of tumor cells in vitro are in agreement with the DNA-binding studies.
X‐ray measurements at 100 K and quantum‐mechanical calculations showed a domination of the enol (OH) form in o‐hydroxyaryl ketones [6‐methoxy‐2‐hydroxyacetophenone (6OMeK), 4‐methoxy‐2‐hydroxyacetophenone (4OMeK), 5‐chloro‐4‐methyl‐2‐hydroxybenzophenone (5Cl4MeK) and 2‐hydroxyacetonaphthone (o‐HAN)], whereas a prevailing proton‐transfer (NH) form was found in o‐hydroxyacetonaphthylimine [2‐(N‐methyl‐α‐iminoethyl)naphthol (o‐HIN)]. The effective mechanism of the reduction in hydrogen bridge length due to steric repulsion in the o‐hydroxyaryl ketones is presented. The following phenomena were found: a decrease in phenol ring aromaticity caused by the proton‐transfer process, dependence of the HOMA index of aromaticity on the HOSE index defining the destabilization of the chelate ring and a dependence of the HOMA index on the lengths of the carbonyl bonds. Moreover, a correlation between phenol ring aromaticity [HOMA(phenol)] and the pseudo‐aromatic ring [HOSE(chelate)] is shown. Correlations between structural parameters of the chelate ring [d(C—O), d(Caryl—Calkyl)] and aromatic rings [HOMA(phenol)] of the o‐hydroxyaryl ketimines and ketones are presented. Copyright © 2005 John Wiley & Sons, Ltd.
The new, water soluble, aminomethylphosphines were synthesized from P(CH 2 OH) 3 and alkylpiperazines: P(CH 2 N(CH 2 CH 2 ) 2 NCH 3 ) 3 (1) and P(CH 2 N(CH 2 CH 2 ) 2 NCH 2 CH 3 ) 3 (2). Described already in literature P(CH 2 N(CH 2 CH 2 ) 2 O) 3 (3) were also obtained. The spectroscopic 1 H, 31 P and 13 C NMR analyses and crystallographic studies of 1, 2 and 3 demonstrate that all these compounds have similar structures and spectroscopic properties, which almost do not depend on aliphatic rings in the molecules. Heteroleptic copper(I) iodide complexes with phosphines mentioned above and 2,2 0 -bipyridine (bpy): [CuI(bpy) 3 ] (3P) were also synthesized. All complexes were characterized by 1 H, 31 P and 13 C NMR spectroscopy also. Molecular structures of 1PÁPhCH 3 and 3PÁ0.5Cu 2 I 2 (phen) 2 were determined from single crystal X-ray diffraction studies. Upon excitation at 470 nm, all complexes in the solid state exhibit red photoluminescence due to charge transfer transition. The luminescence of phen complexes is higher than the luminescence of bpy ones. The presented phosphines and copper(I) complexes were screened for their in vitro antibacterial and antifungal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus strains and Candida albicans. All the copper complexes exhibit significant antibacterial activity against Staphylococcus aureus strains. The activity of 1,10-phenanthroline complexes is higher than 2,2 0 -bipyridine complexes.
The rhodium(III) complex mer,cis-[RhCl3(PPh2py-P,N)(PPh2py-P)] (1) (PPh2py = diphenyl (2-pyridyl)phosphine) has been prepared from RhCl3 x 3H2O and PPh2py and converted to the trans,cis-[RhCl2(PPh2py-P,N)2]PF6 (2) in acetone solution by treatment with Ag+ and PF6(-). Ruthenium(III) and ruthenium(II) compounds with PPh2py, mer,cis-[RuCl3(PPh2py-P,N)(PPh2py-P)] (3) and mer-[RuCl(PPh2py-P,N)2(PPh2py-P)]Cl (5) have been obtained from DMSO precursor complexes. In a chloroform solution, complex (5) isomerizes to fac-[RuCl(PPh2py-P,N)2(PPh2py-P)]Cl (fac-5). All compounds have been characterized by MS, UV-vis, IR, and 1H and 31P{1H} NMR spectroscopy, and the Ru(III) compound has been characterized by EPR spectroscopy as well. The crystal structures of 1, 2, 3, and fac-5 have been determined. In all compounds under investigation, at least one pyridylphosphine acts as a chelate ligand. The 31P chemical shifts for chelating PPh2py-P,N depend on the Ru-P bond lengths.
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