Complexations of the hydrophilic and hydrophobic moieties of benzethonium chloride by cucurbit[7]uril in aqueous solution

2012 ◽  
Vol 90 (10) ◽  
pp. 851-857 ◽  
Author(s):  
Brendan C. MacGillivray ◽  
Donal H. Macartney
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Stability Constant ◽  
Guest Molecule ◽  
Ionization Mass ◽  
H Nmr ◽  
Benzethonium Chloride ◽  
End Groups ◽  
Initial Binding

The sequential complexations of the hydrophilic and hydrophobic end groups of benzethonium chloride by cucurbit[7]uril (CB[7]) in aqueous solution have been investigated using 1H NMR spectroscopy and electrospray ionization mass spectrometry. The initial binding is to the benzyldimethylammonium group, with a stability constant of (8.7 ± 3.1) × 107 (mol/L)–1. This binding constant and the complexation-induced upfield shifts of the benzyl guest protons are similar to those values observed with other cationic guests containing benzyl moieties. This equilibrium is followed by the binding of a second equivalent of the host to the hydrophobic 2-(2,4,4-trimethylpentyl) group, with a stability constant of (4.0 ± 1.9) × 103 (mol/L)–1. The relatively strong binding of this uncharged hydrophobic end of the guest molecule is consistent with the inclusion of eight heavy (nonhydrogen) atoms within the inner cavity of CB[7], with its low polarizability. The packing coefficient for the 2-(2,4,4-trimethylpentyl) group with the inner cavity is calculated to be 61%, close to Rebek’s ideal value of 55%.

Cucurbit[7]uril host-guest complexes with cationic bis(4,5-dihydro-1H-imidazol-2-yl) guests in aqueous solution

2006 ◽  
Vol 84 (6) ◽  
pp. 905-914 ◽  
Author(s):  
D Saroja N Hettiarachchi ◽  
Donal H Macartney
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Stability Constants ◽  
Electrospray Mass Spectrometry ◽  
Hydrophobic Core ◽  
Guest Complex ◽  
H Nmr ◽  
Host Guest Complex ◽  
Proton Resonances

The host–guest interactions between cucurbit[7]uril and a series of novel cationic bis(4,5-dihydro-1H-imidazol-2-yl)arene and 1-(4,5-dihydro-1H-imidazol-2-yl)- and 1,3-bis(4,5-dihydro-1H-imidazol-2-yl)-adamantane guests have been investigated in aqueous solution using UV–vis and NMR spectroscopy, and electrospray mass spectrometry. With the exception of the 1,3-bis(4,5-dihydro-1H-imidazol-2-yl)adamantane (which binds externally to the CB[7]), these guests form very stable inclusion complexes with slow exchange on the 1H NMR timescale. The direction and magnitude of the complexation-induced shifts (CIS) in the proton resonances of the guests are indicative of the residence of the hydrophobic core of the guest within the CB[7] cavity and the charged 4,5-dihydro-1H-imidazol-2-yl units outside the cavity adjacent to the carbonyl-lined portals of the host. The CIS values and the inclusion stability constants have been correlated with the nature of the guest core and with the distance between the charges on the terminal 4,5-dihydro-1H-imidazol-2-yl rings.Key words: cucurbit[7]uril, host–guest complex, dihydroimidazolyl, inclusion stability constants.

scholarly journals A multi-pronged mechanistic study of the phosphine-mediated conjugate addition of an alcohol to an acetylenic ester

2014 ◽  
Vol 38 (11) ◽  
pp. 5382-5390 ◽  
Author(s):  
Rhonda L. Stoddard ◽  
Jingwei Luo ◽  
Nicole van der Wal ◽  
Natasha F. O'Rourke ◽  
Jeremy E. Wulff ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Conjugate Addition ◽  
Ionization Mass Spectrometry ◽  
Mechanistic Study ◽  
Ionization Mass ◽  
Acetylenic Ester ◽  
H Nmr

The conjugate addition of an alcohol to a butynoate ester using an organophosphine catalyst was monitored using pressurized sample infusion electrospray ionization mass spectrometry (PSI-ESI-MS), together with 31P and 1H NMR spectroscopy.

scholarly journals Alkyl substituted 4-pyrrolidinopyridinium salts encapsulated in the cavity of cucurbit[10]uril

2019 ◽  
Vol 43 (18) ◽  
pp. 7028-7034 ◽  
Author(s):  
Weitao Xu ◽  
Ming Liu ◽  
Mary Clare Escaño ◽  
Carl Redshaw ◽  
Bing Bian ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Aqueous Solution ◽  
Nmr Spectroscopy ◽  
Absorption Spectroscopy ◽  
Electronic Absorption ◽  
Electronic Absorption Spectroscopy ◽  
H Nmr ◽  
Pyridinium Nitrogen

The interaction between cucuribit[10]uril (Q[10]) and a series of 4-pyrrolidinopyridinium salts bearing aliphatic substituents at the pyridinium nitrogen, namely 4-(C4H8N)C5H5NRBr, where R = Et (g1), n-butyl (g2), n-pentyl (g3), n-hexyl (g4), n-octyl (g5), n-dodecyl (g6), has been studied in aqueous solution by 1H NMR spectroscopy, electronic absorption spectroscopy and mass spectrometry.

N-Dimethylphosphinoyl-substituted Aminomethanephosphonic Acids

2010 ◽  
Vol 65 (5) ◽  
pp. 556-564 ◽  
Author(s):  
Victoria Lachkova ◽  
Sabi Varbanov ◽  
Walter Frank ◽  
Helmut Keck
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Electrospray Ionization ◽  
Elemental Analysis ◽  
Electrospray Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr

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.

scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

scholarly journals Linkage of α-cyclodextrin-terminated poly(dimethylsiloxanes) by inclusion of quasi bifunctional ferrocene

2013 ◽  
Vol 9 ◽  
pp. 1278-1284 ◽  
Author(s):  
Helmut Ritter ◽  
Berit Knudsen ◽  
Valerij Durnev
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Light Scattering ◽  
Ir Spectroscopy ◽  
Nmr Spectra ◽  
H Nmr ◽  
Scattering Measurements ◽  
End Groups ◽  
2D Roesy ◽  
2D Roesy Nmr

We report the noncovalent linkage of terminally substituted oligo(dimethylsiloxanes) bearing α-cyclodextrins (α-CD) as host end groups for the cyclopentadienyl rings of ferrocene. This double complexation of unsubstituted ferrocene leads to a supramolecuar formation of the siloxane strands. Structural characterization was performed by the use of 1H NMR and IR spectroscopy and by mass spectrometry. Electron microscopy studies and dynamic light scattering measurements show a significant decrease of the derivative size after the complexation with ferrocene. In addition, further evidence for the successful complexation of the end groups was verified by the shifts of the protons in the 1H NMR spectra and in the correlation signals of the 2D ROESY NMR spectra.

Chemie polyfunktioneller Liganden, 69 [1] Über drei Organo-Arsen-Käfigverbindungen mit Noradamantanstruktur / Chemistry of Polyfunctional Ligands, 69 [1] Three Organo-Arsenic Cage Compounds with Noradamantane Structure

1981 ◽  
Vol 36 (12) ◽  
pp. 1532-1537 ◽  
Author(s):  
Jochen Ellermann ◽  
Martin Lietz
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Cage Compounds ◽  
H Nmr ◽  
New Compounds

Abstract The reaction of l.l.l-tris(diiodarsinomethyl)ethane, CH3C(CH2Asl2)3 (1), with H2C(COOC2H5)2, H2C(COOCH3)2 and H2C(COC6H5)2 in presence of the auxiliary base (C2H5)3N gives the noradamantane structured compounds CH3C(CH2As)3E2 [E=C(COOC2H 5)2 (2), C(COOCH3)2 (3) and C(COC6H5)2 (4)].The new compounds have been characterized by mass spectrometry and infrared, Raman and 1H NMR spectroscopy.

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