scholarly journals Matrix Effects on the Chiral Recognition Determined by the Relative Peak Intensity of Diastereomeric Host-Guest Complex Ions Using the FAB Mass Spectrometry/Enantiomer Labeled Guest Method.

2002 ◽  
Vol 50 (6) ◽  
pp. 290-295 ◽  
Author(s):  
Motohiro SHIZUMA ◽  
Hitoshi YAMADA ◽  
Hiroshi ADACHI ◽  
Yoshio TAKAI ◽  
Tokuji TAKEDA ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Chiral Recognition ◽  
Matrix Effects ◽  
Complex Ions ◽  
Guest Complex ◽  
Host Guest Complex ◽  
Peak Intensity ◽  
Fab Mass Spectrometry ◽  
Relative Peak Intensity

Letter: Fast Atom Bombardment, Electrospray, Ionspray and Tandem Mass Spectrometry of 1:1 β-Cyclodextrin/5-Methoxytryptamine Hydrochloride Host—Guest Complex: Host Protonation and Fragmentation Due to Guest Deamination

2000 ◽  
Vol 6 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Andrea Mele ◽  
Walter Panzeri ◽  
Antonio Selva ◽  
Pierluigi Mauri
Keyword(s):  
Mass Spectrometry ◽  
Fast Atom Bombardment ◽  
Ion Trap ◽  
Primary Amines ◽  
Tandem Ms ◽  
Tandem Mass ◽  
Triple Quadrupole ◽  
Guest Complex ◽  
Host Guest Complex ◽  
Pressure Chemical

The 1:1 inclusion complex of β-cyclodextrin (βCD) with 5-methoxytryptamine (5MTA) hydrochloride was studied by mass spectrometry (MS) and tandem-MS with fast atom bombardment (FAB), electrospray (ES) and ionspray (IS) ionisation and triple quadrupole or ion trap analysers. A protonated 1:1 βCD/MTA gaseous association was always observed; the protonated species of deaminated 5MTA and of some typical βCD fragments were obtained, in addition to the expected protonated 5MTA, as tandem-MS dissociation products. A reaction pattern starting from the deamination of protonated 5MTA, as a recently described high pressure chemical ionisation or ES process of primary amines, was suggested, which accounts for the formation of excited protonated βCD and its fragmentation by tandem-MS, even under unimolecular conditions.

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 study of formation and fragmentation of ionic metal complexes of substituted benzoic and cinnamic acids with Al(III)–glycerol by fast atom bombardment mass spectrometry

1997 ◽  
Vol 75 (4) ◽  
pp. 398-404
Author(s):  
Mandapati Saraswathi ◽  
Jack M. Miller
Keyword(s):  
Mass Spectrometry ◽  
Carboxylic Acid ◽  
Metal Complexes ◽  
Spectral Data ◽  
Fast Atom Bombardment ◽  
Complex Ions ◽  
Cinnamic Acids ◽  
Collisionally Activated Dissociation ◽  
Fab Mass Spectrometry

Substituted benzoic and cinnamic acids were studied by FAB mass spectrometry using matrix-based Al(III) ions. Complex ions derived from these acids, such as ( M + 117 )+ ( 117 = (Al + glycerol − 2H)+ ), ( M + 159 )+ ( 159 = [2Al + 2glycerol − 5H − 74(epoxypropanol)]+), and ( M + 233)+ ( 233 = (2Al + 2glycerol − 5H)+), when subjected to collisionally activated dissociation (CAD), gave an ion corresponding to ( M − OH)+. Formation of this ion was explained by the transfer of the carboxylic -OH group to the ( Al + glycerol − 2H)+, ( 2Al + 2glycerol − 5H − 74 )+, and ( 2Al + 2glycerol − 5H )+ portion of the complexes. This transfer is more pronounced in the case of meta- and para-substituted acids. The CAD of the ( M + 117 )+ ions yielded ( M + Al(III) )+ ions resulting from the insertion of Al(III) into the carboxylic acid, which was followed by the elimination of CO to produce ( M + Al(III) − CO)+ ions. Interpretation of spectral data was clarified by study of the formation and fragmentation of ions produced from deuterated benzoic and cinnamic acids. Keywords: substituted benzoic and trans-cinnamic acids, Al(III)–glycerol, FAB mass spectrometry, ionic metal complexes, collisionally induced dissociation, Al(III) insertion, carbonyl cations.

scholarly journals Metalloporphyrin Dimers Bridged by a Peptoid Helix: Host-Guest Interaction and Chiral Recognition

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2741 ◽  
Author(s):  
Yen Lee ◽  
Boyeong Kang ◽  
Jiwon Seo
Keyword(s):  
Drug Delivery ◽  
Molecular Recognition ◽  
Complex Formation ◽  
Asymmetric Catalysis ◽  
Spectroscopic Data ◽  
Chiral Recognition ◽  
Guest Complex ◽  
Molecular Sensing ◽  
Host Guest Complex ◽  
Chirality Induction

Co-facial porphyrins have been designed to construct porphyrin tweezers with versatile molecular recognition capabilities. In this study, we synthesized metalloporphyrin–peptoid conjugates (MPPCs) displaying two metalloporphyrins on a peptoid scaffold with either achiral unfolded (1) or helical (2 and 3) secondary structures. Host–guest complexation of MPPCs was realized with various guests of different lengths and basicities, and the extent of complexation was measured by UV-vis and circular dichroism (CD) spectroscopic titration. Intermolecular and intramolecular chirality induction were observed on achiral and chiral peptoid backbones, respectively. Spectroscopic data indicated that a broad scope of achiral guests can be recognized by chiral 2; in particular, longer and more flexible guests were seen to bind more tightly on 2. In addition, chiral 2 provided a distinct CD couplet with dl-, d-, or l-Lys-OMe, which was a result of the diastereomeric host–guest complex formation. Our results indicated that MPPCs can recognize, contrast, and analyze various achiral, chiral, or racemic molecules. Based on co-facial metalloporphyrins present on peptoid scaffolds, we developed a novel class of porphyrin tweezers, which can be further utilized in asymmetric catalysis, molecular sensing, and drug delivery.

scholarly journals UV photodissociation spectroscopy of cryogenically cooled gas phase host–guest complex ions of crown ethers

2015 ◽  
Vol 17 (39) ◽  
pp. 25925-25934 ◽  
Author(s):  
Yoshiya Inokuchi ◽  
Takeharu Haino ◽  
Ryo Sekiya ◽  
Fumiya Morishima ◽  
Claude Dedonder ◽  
...  
Keyword(s):  
Gas Phase ◽  
Crown Ethers ◽  
Electronic Spectra ◽  
Complex Ions ◽  
Guest Complex ◽  
Dramatic Effect ◽  
Host Guest Complex ◽  
Guest Species ◽  
Fragmentation Patterns

Crown ethers show a dramatic effect on the electronic spectra and fragmentation patterns of guest species.

Conglomerate crystallization, chiral recognition and spin-crossover in a host–guest complex consisting of FeIII complexes (host) and [Cr(ox)3]3− (guest)

CrystEngComm ◽  
2012 ◽  
Vol 14 (20) ◽  
pp. 6377 ◽  
Author(s):  
Yukinari Sunatsuki ◽  
Sho Miyahara ◽  
Yuu Sasaki ◽  
Takayoshi Suzuki ◽  
Masaaki Kojima ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Spin Crossover ◽  
Guest Complex ◽  
Host Guest Complex ◽  
Conglomerate Crystallization
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