Synthesis and Spectroscopic, Thermal and Electrochemical Studies of Mixed-ligand Complexes of Silver(I) with Derivatives of Benzoyltrifluoroacetonate and 4,4ʹ-Bipyridine, Including the Crystal Structure of [Ag(4,4ʹ-bpy)(tfcpb)]n

2012 ◽  
Vol 67 (5) ◽  
pp. 465-472 ◽  
Author(s):  
Farzin Marandi ◽  
Afsaneh Marandi ◽  
Ingo Pantenburg ◽  
Gerd Meyer

Three new mixed-ligand complexes of silver(I) with 4,4ʹ-bipyridine and derivates of benzoyltrifluoroacetone (Htfpb: 4,4,4-trifluoro-1-phenyl-1,3-butandione, Htfcpb: 4,4,4-trifluoro-1-(4- chlorophenyl)-1,3-butandione and Htfmpb: 4,4,4-trifluoro-1-(4-methoxyphenyl)-1,3-butandione) were synthesized and characterized by elemental analyses and 1H NMR spectroscopy. Thermal and electrochemical properties were also studied. The single-crystal structure of [Ag(4,4ʹ-bpy)(tfcpb)]n shows a one-dimensional coordination polymer as a result of 4,4ʹ-bpy bridging. The four-coordinate Ag(I) ions are linked into double chains by Ag...O contacts, which are extended into a 3D supramolecular structure through abundant weak interactions, such as μ...μ, C-H...F, C-H...O, C-H...Cl and F...F contacts.

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1576-1586 ◽  
Author(s):  
Sara Pfister ◽  
Luca Sauser ◽  
Ilche Gjuroski ◽  
Julien Furrer ◽  
Martina Vermathen

The encapsulation of five derivatives of chlorin e6 with different hydrophobicity and aggregation properties into a series of five poloxamer-type triblock copolymer micelles (BCMs) with varying numbers of polyethylene and polypropylene glycol (PEG, PPG) units was monitored using 1H NMR spectroscopy. NMR chemical shift and line shape analysis, as well as dynamic methods including diffusion ordered spectroscopy (DOSY) and T1 and T2 relaxation time measurements of the chlorin and the polymer resonances, proved useful to assess the chlorin–BCM compatibility. The poloxamers had high capability to break up aggregates formed by chlorins up to intermediate hydrophobicity. Physically entrapped chlorins were always localized in the BCM core region. The loading capacity correlated with chlorin polarity for all poloxamers among which those with the lowest number of PPG units were most efficient. DOSY data revealed that relatively weakly aggregating chlorins partition between the aqueous bulk and micellar environment whereas more hydrophobic chlorins are well retained in the BCM core region, rendering these systems more stable. T1 and T2 relaxation time measurements indicated that motional freedom in the BCM core region contributes to encapsulation efficiency. The BCM corona dynamics were rather insensitive towards chlorin entrapment except for the poloxamers with short PEG chains. The presented data demonstrate that 1H NMR spectroscopy is a powerful complementary tool for probing the compatibility of porphyrinic compounds with polymeric carriers such as poloxamer BCMs, which is a prerequisite in the development of stable and highly efficient drug delivery systems suitable for medical applications like photodynamic therapy of tumors.


2011 ◽  
Vol 46 (9) ◽  
pp. 4537-4547 ◽  
Author(s):  
Verasuntharam M. Manikandamathavan ◽  
Royapuram P. Parameswari ◽  
Thomas Weyhermüller ◽  
Hannah R. Vasanthi ◽  
Balachandran Unni Nair

1988 ◽  
Vol 43 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Whei Oh Lin ◽  
Maria C. B. V. de Souza ◽  
Helmut G. Alt

The synthesis of trans-1.2-cyclohexanedioxydiacetamides starting with trans-1.2-cyclohexane-diol is described. Eleven of these compounds are characterized by IR, 1H NMR, 13C NMR and mass spectroscopy as well as elemental analyses. Most of these compounds are suitable ionophors for the cations K+ and Ca2+. The coordination sites of these ligands in the 1:2 complexes were determined by IR and NMR spectroscopy


2009 ◽  
Vol 6 (4) ◽  
pp. 1085-1090
Author(s):  
Farzin Marandi ◽  
Lotfali Saghatforoush ◽  
Hossein Farzaneh

To investigate the interactions between noncovalent bond donor and acceptor giving rise to three dimensional networks, compound [Pb2(dmp)2(hfacac)2] (1) (dmp = 2,9-dimethyl-1,10-henanthroline and Hhfacac = hexafluoroacetylacetonate) has been prepared and characterized by elemental analysis, IR,1H NMR, and13C NMR spectroscopy and its crystal structures was investigated. The single crystal structure show the coordination number of Pb(II) to be eight with twoN-donor atoms from a “dmp” ligand and sixO-donors from the anionic ligands. The supramolecular structure of 1 is realized by weak directional C–H∙∙∙O–C, C–F∙∙∙F–C andπ–πstacking interactions.


2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.


2011 ◽  
Vol 306-307 ◽  
pp. 228-233
Author(s):  
Jin Liang Zhu ◽  
Sheng Li Liu ◽  
Liang Cai Yu ◽  
Tao Ouyang

A new ligand, 1,1'-(pyridin-2,6-diyl)bis-3-p-tolylpropane-1,3-dione(H2L), was prepared and its crystal structure displays its enol isomer. The binary complex, Ln2L3·4H2O [Ln = Eu(III) and Tb(III)], were synthesized by the reaction of synthesized ligand (H2L) and Ln(III). With 1,10-phenanthroline (Phen) as the synergistic ligand, the ternary complex, Ln2L3(Phen)2 [Ln = Eu(III) and Tb(III)], were synthesized. The compounds were characterized by 1H-NMR spectroscopy, MS, IR, UV, DTA-TG and fluorescence spectrum. The luminescent properties of the ligand and its complexes were investigated and the results showed that the prepared ligand was a good luminescent compound, all complexes emitted characteristic luminescence of corresponding lanthanide ions and 1,10-phenanthroline as the synergistic ligand can obviously enhance the luminescence of Eu(III) in the ternary complex.


2003 ◽  
Vol 81 (5) ◽  
pp. 364-375 ◽  
Author(s):  
Jonathan Watts ◽  
Jesús Jiménez-Barbero ◽  
Ana Poveda ◽  
T Bruce Grindley

The conformations of a series of derivatives of the disaccharide α-L-fucopyranosyl-(1[Formula: see text]3)-2-acetamido-2-deoxy-D-glucopyranoside, part of the Lex determinant, were studied by molecular modelling using the MM3* forcefield and by 1H NMR spectroscopy. Unusually shielded O-benzyl protons were observed in the 1H NMR spectrum of phenyl 2,3,4-tri-O-benzyl-α-L-fucopyranosyl-(1[Formula: see text]3)-2-deoxy-2-phthalimido-1-thio-α-D-glucopyranoside and assigned to the 2-O-benzyl group. This observation was explained by a shift in the population of the conformational mixture present about the glycosidic linkage from the positive Ψ region in the unsubstituted disaccharide to the negative Ψ region induced by π-stacking between the phthalimide and the 2-O-benzyl phenyl ring. The experimental nuclear Overhauser enhancements confirm the accuracy of the calculations.Key words: disaccharide, conformation, π-stacking, Lex determinant, NOE measurements, MM3 calculations.


Sign in / Sign up

Export Citation Format

Share Document