In (CMHC)'s FT-IR spectrum, phenolic OH strain 3270 cm-1, aromatic and aliphatic C-H strains at 3085-2850 cm-1, respectively, - OC=O (the peak belongs to carbonyl group
on coumarin ring) at 1695 cm-1, aromatic C=C double bond strain at 1615 cm-1, aliphatic C-H bending vibration at 1440-1315 cm-1 are the most characteristic peaks for the structure.
Due to the importance of the band corresponding to the carbonyl group
to the possible interaction with the hydroxyl groups of anhydroglucose units of the starch, the deconvolution technique was used to clarify the overlapping effect of the bands, where the contribution of each one of them can be separated.
As the N-H groups in the isocyanates can form hydrogen bonds either with the carbonyl group
of the adjacent hard segment or with the ether functional group of the soft segment, depending on the domain in which they are included .
The molecules at the heart of the proposal are compounds containing a carbon-oxygen double bond (a carbonyl group
) which have special properties and are the building blocks of many known pharmaceutical agents.
Key statement: Acido-basic properties of a system containing a polymer fragment obtained by oxidative cleavage of a carbon-carbon double bond of a diene rubber polymer and a functional molecule having in a structure thereof an alkoxysilyl group and at least one functional group selected from the group consisting of an aldehyde group and a carbonyl group
are changed such that the system becomes basic when acidic, and becomes acidic when basic, thereby combining the polymer fragment with the functional molecule to form a modified diene rubber polymer having an alkoxysilyl group incorporated therein.
Furthermore, it was assumed that the signals of two of the three carbonyl functionalities overlapped to give the intense signal at [[delta].sub.C] 164.17 ppm besides the signal at [[delta].sub.C] 164.94 ppm assigned to the other carbonyl group
. A close inspection of the 3D view (Figure 2) of the optimized structure geometry of compound 7 clearly reveals that the electron clouds of the carbonyl groups
of the two 3-diazenyl-4H-thieno[3,4-c]chromen-4-one moieties attached at positions -3 and -5 of the central phenolic ring are virtually more involved in the interactions with the electron clouds of the neighboring atoms and groups than the carbonyl group
of the 3-diazenyl-4H-thieno[3,4-c]chromen-4-one moiety fixed at position -2 of the core phenolic ring.
Moreover, there were three bands at 772, 656, and 505 [cm.sup.-1] corresponding to the carbonyl group
. At 400[degrees]C, the hydroxyl groups disappeared due to dehydration, while C=O and C-H bands were diminished.
Also the strong band of methoxy carbonyl group
in biodiesel is at different position as compared to PCOs and WFOs.
As for low molecular carbonyl compounds, the carbonyl group
was activated by the ionization through proton transfer reaction, and [H.sub.2]O (m/z 57 [right arrow] 39, m/z 59 [right arrow] 41, m/z 71 [right arrow] 53, and m/z 73 [right arrow] 55) or CO (m/z 57 [right arrow] 29, m/z 71 [right arrow] 43, and m/z 73 [right arrow] 45) was easy to lose in the collision cell [22,23].
2008), the resonance structure containing the single bonded CO is stabilized yielding a lower wavenumber infrared absorption of the carbonyl group
. Figure 6 shows this oxygen lonepair donation process, and describes its impact on the carbonyl absorption.
The carbonyl group
maintained the same intensity, with small fluctuations, across the different thermal treatment conditions.
The upfield or in some cases downfield shift of this signals in the spectra of complexes of these ligands, reveals that carbonyl group
of SO2NHCO moiety in the ligand is involved in coordination with metals.