Trans-2- 3- -2-methyl-2-propenylidene malononitrile

Pyrene is used commercially to make dyes and dye precursors. It was used by Jarroux et al. [37] as a MALDI matrix for the analysis of a poly(ethylene oxide) sample terminated with pyrene on both sides. trans-2-[3-(4-tert-Butylphenyl)-2-methyl-2-propenylidene]malononitrile is a relatively new matrix (it was introduced in 2003). This matrix possesses a very low threshold, probably lower than HABA. 

Finally, MALDI-TOF MS characterization of poly-6-AO-BF3k [DCTB (trans-2-[3-(4-f rf-butylphenyl)-2-methyl-2-propenylidene]malononitrile) was found to be the best matrix] showed that the most intense peaks correspond to the molecular ions (M+) of polybenzofulvene oligomers terminated with hydrogen at both ends (H/H, species An in Fig. 42) and the second intense peak series belongs to the molecular ions of macromolecules bearing an aldehyde moiety (H/CHO species Bn),... 

In this context, dialdehyde la (5 mg, 0.017 mmol), sarcosine (14 mg, 0.157 mmol) and five-fold excess of Ceo (60 mg, 0.083 mmol) dissolved in 10 ml of o-dichlorobenzene (o-DCB) heated at 130 °C for 90 min. After a typical work up procedure, the reaction mixture is purified by recycling HPLC on a preparative Buckyprep Cosmosil column (250 X 20 mm, toluene eluent, lOml/min flow rate) to furnish bis-fullerene derivative 3 in 32 % yield. The bis-fullerene 3 shows moderate solubility, thus allowed us to record and NMR spectra (Supp. Info., Fig. SI) corroborating the depicted structure in Scheme 1. The attenuated-total-reflectance infra-red (ATR-IR) spectrum of 3 demonstrates the characteristic stretching vibrations of the C-H (2803-3030cm" ) as well as the characteristic absorptions for fullerenes (Supp. Info., Fig. S2). Matrix-assisted-laser-desorption time-of-flight mass-spectroscopy (MALDI-TOF-MS), in the negative ionization mode and with the aid of trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile shows the molecu-... 

Solvents were purchased from Fluka and Panreac, reagents were purchased from Aldrich and Fluka and C o was purchased from SES Research. Silica gel 60, 70-230 mesh was used in column chromatography. HPLC separations were performed on a LC-9101 instrument using a Cosmosil Buckyprep 20 x 250 mm preparative column and toluene as mobile phase at lOmL/min. Melting points were measured on a Buchi instrument. NMR spectra were recorded on Bruker AV-500 and 300 spectrometers. MALDI-TOF negative ionization mass spectra were recorded on a Shimadzu spectrometer, using trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile as matrix. UV-Vis spectra were recorded... 

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See also in sourсe #XX -- [ ]

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