methylidyne

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methylidyne

[me′thil·ə‚dīn]
(organic chemistry)
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The 13C NMR spectrum (Table-1) of 2 fully supported the 1H-NMR data as it displayed eight signals, which were identified as one methyl (I' 14.9), two methylene (I' 41.1 and 61.8), two methine (I' 130.1 and I' 120.1) and three quaternary carbons (I' 156.2, 138.1 and 137.5), on the basis of DEPT experiments.
The TGA and DTG curves of PF resins that include divalent metal ions and control samples demonstrated that ortho hydroxyl methylation is the most dominant reaction in the uncured resin triggered with [Ba.sup.2+] as the catalyst, resulting in a high content of ortho methine linkages, leaving the para position, which has the highest reactivity, unreacted (Chen et al.
CH), 1580 [cm.sup.-1] (-N=CH) NMR: [.sup.1]H NMR ([DMSO-d.sub.6], 300 MHz,): [delta]=6.95-7.35 (m, 9H, aromatic H), 4.95-5.90 (s, 2H, methine), 3.35 (s, 2H, methylene), 4.85 (s, 1H, ethylene).
The four peaks assigned for methyl (C[H.sub.3], 21.2 ppm), methylene (C[H.sub.2], 42.7 ppm), methine (CH, 68.5 ppm) and carbonyl (C=O, 169.7 ppm) carbon resonance of PHA 54.
The [.sup.13.]C-NMR (BB and DEPT) spectra showed well resolved total nineteen carbon signals comprising four methyl, five methine and ten quaternary carbon atoms.
The 'H-NMR signals are assigned and the area ratio of methine of PG unit (peak d, Fig.
Another olefinic methine proton is observed at [delta] 5.5 (1H, d).
A singlet at [delta] 1.98 is due to the methylene protons (C[H.sub.2]-CH=CH) adjacent to the methine carbon in unsaturated fatty acids [24].
Methine protons of CH=[N.sup.+] fragments are observed as singlet signals in the region of 7.10-7.30 ppm.
The characteristic peaks at 1.5, 4.8, and 5.2 ppm belonged to the methyl (d, -C[H.sub.3]), methane (m, -C[H.sub.2]), and methine (m, -CH) proton of the PLGA segment, respectively.
1610) of structural [H.sub.2]O] [4] 1541 Collagen (Amide II) 1440 [delta]C[H.sub.2] [4] 1415 [delta]ipC-O-H (carboxylic side chains), SN[H.sub.2] [4], [v.sub.3] asymmetric of C[O.sub.3]= [3, 31] 1333 [omega]C[H.sub.2]/[delta]C-H (methine) [4] 1236 Amide III [3] vC-O-C and [delta]C-H [3] N[H.sub.3] + residual modes [30] 1140 (sh) [v.sub.3] calcium sulphate [4] 1113 Gypsum ([v.sub.3] S[O.sub.4.sup.=]) [4] 1080 (sh) vC-O or skeletal ] [30] 1034 vC-N [30]or vC-O-C and vC-O [3] 874 [v.sub.2] asymmetric of C[O.sub.3.sup.=] [3, 25] 711 (sh) [v.sub.4] symmetric of C[O.sub.3.sup.=] 670 Gypsum ([[delta].sub.antis] S[O.sub.4.sup.=]) 602 Gypsum ([v.sub.4as] S[O.sub.4.sup.=]) [4] v = stretching; [delta] = bending; d = deformation; ip = in-plane; sh = shoulder.
Combining with DEPT NMR, the compound contains 5 quaternary carbon signals, 9 methine signals, and 2 methylene signals.

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