Deuteron NMR resolved mesogen vs. crosslinker molecular order and reorientational exchange in liquid single crystal elastomers

2016 ◽  
Vol 18 (5) ◽  
pp. 4071-4077 ◽  
Author(s):  
J. Milavec ◽  
V. Domenici ◽  
B. Zupančič ◽  
A. Rešetič ◽  
A. Bubnov ◽  
...  

2H NMR spectroscopy can resolve differences in orientational order and reorientational dynamics between crosslinker and mesogen molecules in liquid single crystal elastomers.

2020 ◽  
Vol 75 (12) ◽  
pp. 1043-1048
Author(s):  
Farzin Marandi ◽  
Harald Krautscheid

AbstractA dinuclear and a tetranuclear complex of lead(II) with the pincer-type ligand 4′-(4-chlorophenyl)-2,2′:6′,2″-terpyridine (Cl-Ph-tpy), [Pb2(Cl-Ph-tpy)2(μ-I)2I2] (1) and [Pb4(Cl-Ph-tpy)4(μ-Br)4(μ-OH2)Br4]·2CH3OH (2), have been synthesized and characterized by elemental analysis, FT-IR and 1H NMR spectroscopy, and by single-crystal X-ray diffraction. In the binuclear structure of 1, the Pb atom has a hemidirected PbN3I3 environment with a Pb(μ-I)2Pb central unit. In the tetranuclear structure of 2, two crystallographically independent Pb(II) centres having hemidirected PbN3Br3 and PbN3OBr2 environments are connected to Pb(μ-Br)Pb(μ-Br)2(μ-OH2)Pb(μ-Br)Pb chains. The supramolecular features in 1 and 2 are supported through weak but directional C–H···Cl, C–H···I and C–H···Br, C–H···O, O–H···Br, and O···Br interactions and aromatic π-π stacking.


2005 ◽  
Vol 60 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Ali Morsali

1:1 and 1:2 lead(II) complexes with 2,9-dimethyl-1,10-phenanthroline (Dmphen), {[Pb(Dmphen)(NO3)n] and [Pb(Dmphen)2(ClO4)2]} have been synthesized and characterized by CHN elemental analysis, IR, 1H NMR, 13C NMR and 207Pb NMR spectroscopy. The structure of these complexes was confirmed by X-ray crystallography. The single crystal X-ray data of [Pb(Dmphen)(NO3)n] show the complex to be polymeric and the Pb atom to have an unsymmetrical eight-coordinate geometry, the coordination being holodirected, whereas the [Pb(Dmphen)2(ClO4)2] complex is monomeric and the Pb atom has an unsymmetrical eight-coordinate geometry with the coordination hemidirected.


Author(s):  
Paulina Kalle ◽  
Sergei V. Tatarin ◽  
Alexander Yu. Zakharov ◽  
Marina A. Kiseleva ◽  
Stanislav I. Bezzubov

The title compounds, 2-(pyridin-2-yl)-1H-perimidine (C16H11N3; 1), 1-methyl-2-(pyridin-2-yl)-1H-perimidine (C17H13N3; 2), and 1,3-dimethyl-2-(pyridin-2-yl)-1H-perimidinium iodide (C18H16N3 +·I−; 3) were synthesized under mild conditions and their structures were determined by 1H NMR spectroscopy and single-crystal X-ray analysis. The N-methylation of the nitrogen atom(s) at the perimidine moiety results in a significant increase of the interplane angle between the pyridin-2-yl ring and the perimidine system. The unsubstituted perimidine (1) forms a weak intramolecular N—H...N bond that consolidates the molecular conformation. In the crystal structures of 1–3, the molecular entities all are assembled through π–π and C—H...π interactions.


2010 ◽  
Vol 65 (5) ◽  
pp. 556-564 ◽  
Author(s):  
Victoria Lachkova ◽  
Sabi Varbanov ◽  
Walter Frank ◽  
Helmut Keck

Three new N-phosphinoyl-substituted aminomethanephosphonic acids have been synthesized and characterized: dimethylphosphinoylmethyl-imino-bis(methanephosphonic acid) (1), [3-(dimethylphosphinoyl)-propyl]-imino-bis(methanephosphonic acid) (2), and N-benzyl-Ndimethylphosphinoylmethyl- aminomethanephosphonic acid (3). The latter was isolated as a hydrochloride 3 ・ HCl. The acids have been prepared via Moedritzer-Irani reaction from the corresponding dimethylphosphinoyl-substituted primary and secondary aliphatic amines. Their structures have been confirmed by elemental analysis, IR, 1H, 31P{1H}, 13C{1H} NMR spectroscopy, electrospray ionization mass spectrometry, and single-crystal X-ray diffraction.


1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.


1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.


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.


2020 ◽  
Vol 22 (19) ◽  
pp. 11075-11085
Author(s):  
Mengjian Wu ◽  
Zhaoxia Wu ◽  
Shangwu Ding ◽  
Zhong Chen ◽  
Xiaohong Cui

Different submicellar solubilization mechanisms of two systems, Triton X-100/tetradecane and sodium dodecyl sulfate (SDS)/butyl methacrylate, are revealed on the molecular scale by 1H NMR spectroscopy and 2D diffusion ordered spectroscopy (DOSY).


1999 ◽  
Vol 23 (3) ◽  
pp. 178-179
Author(s):  
Wendy I. Cross ◽  
Kevin R. Flower ◽  
Robin G. Pritchard

The acetic acid esters of 1-(4-methylphenylazo)naphthalen-2-ol 1 and 2-(4-methylphenylazo)-4-methylphenol 3 are prepared and characterised by single crystal X-ray diffraction studies and 13C{1H}NMR spectroscopy; the position of the C(2)13C resonance for the ester is used to predict the position of resonant frequency of the equivalent carbon in the parent alcohols and hence, calculate the position of the azo-hydrazone equilibrium in these compounds.


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