A comparison of the electron ionization and electrospray behaviour of some N,N′‐disubstituted hexahydropyrimidines

Orelli, Liliana R.; García, María B.; Perillo, Isabel A.; Tonidandel, L.; Traldi, Pietro

doi:10.1002/rcm.2375

Cited by 12 publications

(10 citation statements)

References 25 publications

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“…A quadrupole ion-trap mass spectrometer equipped with an atmospheric pressure ionization source (ESI/APCI-ITMS) is an efficient tool for multistage tandem (MS [1][2][3][4][5][6][7][8][9][10] ) mass spectrometry, which provides useful information about the structures of analyte ions. [25][26][27] On the other hand, a time-of-flight (TOF) analyzer allows fast acquisition of full spectra with high sensitivity and elevated mass resolution (7000-15 000 FWHM). This usually enables product ions to be assigned with a mass accuracy of $5 ppm allowing, in many cases, unambiguous assignment and definitive designation of the fragmentation pathways.…”

mentioning

confidence: 99%

A fragmentation study of podophyllotoxin and its 4′‐demethyl‐4β‐substituted derivatives by electrospray ionization ion‐trap time‐of‐flight tandem mass spectrometry

Yan

2007

Rapid Comm Mass Spectrometry

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High-resolution electrospray ionization multistage tandem mass spectrometry (MS(1-9)) was used to determine the accurate masses and the fragmentation pathways of protonated podophyllotoxin (1) and its corresponding 4'-demethyl-4beta-substituted derivatives (2-4). The protonated molecules, [M + H](+), of all the four compounds were observed in the conventional single-stage mass spectra. Two fragmentation pathways, that appear to be characteristic of the four compounds, are proposed on the basis of their multistage tandem mass spectrometric data. The characteristic elimination, from the precursor protonated ions, of the neutral groups 4-R(1)H, 1-ArH, CO, CH(2)O and C(4)H(4)O(2), in which R is located on C-4, is the common elimination, and the product ions at m/z 267, 239, 229, 181, 173, 153, 143 and 115 are the common diagnostic masses. The elimination of the R(1) group substituent located on the C-4 position of compounds 1-4 has a significant influence on the fragmentation pathway obtained in the conventional single-stage mass spectra. A large R(1) group would be unfavorable for this elimination, unless the collision energy is raised. Apart from the common fragmentations obtained for the protonated molecules 1-4, significant additional product ions were detected in the various multistage tandem mass spectrometric analyses, particularly in the case of the product ions derived initially from the phenolic hydroxyl group of 2-4, which are different from those of 1. Based on these additional formed product ions, several additional fragmentation pathways for 1 or 2-4 are also presented.

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mentioning

confidence: 99%

A fragmentation study of podophyllotoxin and its 4′‐demethyl‐4β‐substituted derivatives by electrospray ionization ion‐trap time‐of‐flight tandem mass spectrometry

Yan

2007

Rapid Comm Mass Spectrometry

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“…Thus, elimination of HCN from the [L + H] + peaks of the unsubstituted ligands 1 and 2 with different energy values ( 1 E 10% = 35 eV) and ( 2 E 10% = 24 eV) is observed and documents the stabilization of the large surface ligand 1 resulting from well‐known π‐delocalization effects . Corresponding losses of RCN (with R = CH 3 for 4 [ E 10% = 27 eV] and R = Ph for 11 [ E 10% = 34 eV]) are the initial fragmentations of 4 and 11 , respectively, and were reported earlier for similar isoquinoline derivatives …”

Section: Resultsmentioning

confidence: 88%

Electrospray mass spectrometry and molecular modeling study of formation and stability of silver complexes with diazaperylene and bisisoquinoline

et al. 2018

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The complex formation of the following diazaperylene ligands (L) 1,12-diazaperylene 1, 1,1'-bisisoquinoline 2, 2,11-disubstituted 1,12-diazaperylenes (alkyl = methyl, ethyl, isopropyl, 3, 5, 7), 3,3'-disubstituted 1,1'-bisisoquinoline (alkyl = methyl, ethyl, isopropyl, 4, 6, 8 and with R = phenyl, 11 and with pyridine 12), and the 5,8-dimethoxy-substituted diazaperylene 9, 6,6'-dimethoxy-substituted bisisoquinoline 10 with AgBF4 was investigated. Collision-induced dissociation measurements were used to evaluate the relative stabilities of the ligands themselves and for the [1:1] complexes as well as for the homoleptic and heteroleptic silver [1:2] complexes in the gas phase. This method is very useful in rapid screening of the stabilities of new complexes in the gas phase. The influence of the spatial arrangement of the ligands and the type of substituents employed for the complexation were examined. The effect of the preorganization of the diazaperylene on the threshold activation voltages and thus of the relative binding energies of the different complexes are discussed. Density functional theory calculations were used to calculate the optimized structures of the silver complexes and compared with the stabilities of the complexes in the gas phase for the first time.

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“…[17][18][19][20][21][22][23][24][25][26] Besides, a few other ionization methods, such as chemical ionization (CI), electrospray ionization (ESI), have also been reported. [27][28][29][30] Although ESI usually brings out a quasi-molecular ion with little fragmentation information, it provides great advantage in a liquid chromatography/mass spectrometry (LC/MS) technique, which is widely used in high throughput screening combinatorial chemistry. ESI-MS combining with a collision-induced dissociation (CID) method can also offer the structure information, but the fragmentation pathways may be different from those in an EI mode.…”

Section: Introductionmentioning

confidence: 99%

Fragmentation Study of 2‐Amino‐4H‐1,3‐oxazines and Octahydro‐4‐phenyl‐2H‐pyrano[2,3‐d]pyrimidin‐2‐ones: Identification of Heterocyclic Six‐membered Ring in Three‐component Reactions

Tai

Wan

et al. 2009

Chin. J. Chem.

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The fragmentation behavior of ten 2-amino-4H-1,3-oxazines and seven octahydro-4-phenyl-2H-pyrano[2,3-d]-pyrimidin-2-ones was investigated by electrospray ionization tandem mass spectrometry (ESI-MS n ). When the precursor ions were protonated oxazines, two predominant fragmentation pathways were observed with elimination of CH 2 N 2 and HCNO, respectively. The product ion [M＋H-60] ＋ could be observed from both pathways. While in the type of pyrimidin-2-ones, only direct loss of 60 Da (urea) could be observed. The fragmentation pathways were investigated by high-resolution mass spectrometry and deuterium-labeling experiments, and the characteristic fragmentations presented here could be convenient for future identification of resembled derivatives, especially in high throughput screening combinatorial chemistry.

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A comparison of the electron ionization and electrospray behaviour of some N,N′‐disubstituted hexahydropyrimidines

Cited by 12 publications

References 25 publications

A fragmentation study of podophyllotoxin and its 4′‐demethyl‐4β‐substituted derivatives by electrospray ionization ion‐trap time‐of‐flight tandem mass spectrometry

A fragmentation study of podophyllotoxin and its 4′‐demethyl‐4β‐substituted derivatives by electrospray ionization ion‐trap time‐of‐flight tandem mass spectrometry

Electrospray mass spectrometry and molecular modeling study of formation and stability of silver complexes with diazaperylene and bisisoquinoline

Fragmentation Study of 2‐Amino‐4H‐1,3‐oxazines and Octahydro‐4‐phenyl‐2H‐pyrano[2,3‐d]pyrimidin‐2‐ones: Identification of Heterocyclic Six‐membered Ring in Three‐component Reactions

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