Acetamide, molecular structure

We like to conclude the section with the spectacular molecular structure of the octanuclear platinum acetamidate blue [Pt8(NH3)16 (CH3CONH)8]10+, Figure 2, even if no pertinent electrochemical investigation has been carried out.25... 

Chandler, M. et al. Approaches to Carbocyclic Analogues of the Potent Neuraminidase Inhibitor 4-Guanidino-Neu5Ac2en. X-Ray Molecular Structure of N-[(/ S,2S, 6R)-2-azido-6-benzyloxy-methyl-4-formylcyclohex-3-enyl]acetamide. 3.4.1 1995 [112]... 

In these complexes anion coordination must be present with the exception of perchlorate. Lanthanide contraction may also be an influencing factor. The molecular structure [ 189] of Eu(TMU)3(N03)3 shows the presence of bidentate nitrates with a coordination number of nine. The coordination polyhedron is neither the tricapped trigonal prism nor the monocapped square antiprism which may be due to the small bite of nitrate ligand. The dimethyl acetamide (DMA) complexes behave similarly as those of tetramethyl urea (TMU) with less steric requirements as evidenced by the synthesis of [180-182] La(DMA)8(C104)3, La = La-Nd La(DMA)7(C104)3, La=Sm-Er La(DMA)6(C104)3, La = Tm-Lu. 

Jeffrey GA, Ruble JR, McMullan RK, DeFrees DJ, Binkley JS, Pople JA (1980) Neutron diffraction at 23 K and ab-initio molecular orbital studies of the molecular structure of acetamide. Acta Cryst B 36 2292-2299... 

Fig. 3.1. Visualization of a drug molecule N-(4-hydroxy-phenyl)-acetamide (Tylenol or acetaminophen) computerized with different levels of graphic representations. (A) Molecular structure of the drug Tylenol. (B) Ball-stick model showing atomic positions and types. (C) Ball-stick model with van der Waals dot surfaces. (D) Space-filled model showing van der Walls radii of the oxygen, nitrogen, and carbon atoms. (E) Solvent accessible surface model (solid) (solvent radius, 1.4A). (See black and white image.)...

Li, S., et ah. Molecular Dynamics Simulation of Litfsi-Acetamide Electrolytes Structural Properties. J. Phys. Chem. B 2008,112, 6398-6410. 

Next, examine the equilibrium structure of acetamide (see also Chapter 16, Problem 8). Are the two NH protons in different chemical environments If so, would you expect interconversion to be easy or difficult Calculate the barrier to interconversion (via acetamide rotation transition state). Rationalize your result. Hint Examine the highest-occupied molecular orbital (HOMO) for both acetamide and its rotation transition state. Does the molecule incorporate a n bond. If so, is it disrupted upon rotation ... 

Two of amides from melon flies of the genus Dacus (Table VIII) have been identified as V-isoamylacetamide (122) and V-(2-methylbutyl)acetamide (123) by comparison of their mass spectra and chromatographic properties with those of authentic samples 103). The third amide, previously reported neither as a component of an insect secretion nor as a synthesized derivative, was assigned as A-isoamyl-2-methoxyacetamide (124) from the mass spectrum, showing a molecular ion at m/z 159 and fragment ions at m/z 129 (M" — CHjO) and 102 (M + — C4Hg), and its structure was confirmed by comparison with a synthetic au-... 

Similar shortening of the C-N bond and lengthening of the C=0 bond is found when the structures of acetamide [376, 377], fluoroacetamide [299], and thioacetamide [204] in the hydrogen-bonded crystals are compared with ab-initio molecular orbital calculations for the isolated molecule, as shown in Thble 5.4. 

Replacing the two Cl atoms with Br on the acetamide group on C-2 showed about 80% of the activity. The monochloroacetamide retained 40% even the acetamido group without halogens exhibited slight antibacterial properties. In the final analysis, after considerable SAR research, it appears that the structure supplied by S. venezuelae was the optimum structure. This is in contrast to what is seen with other antibiotics where molecular modifications resulted in dramatic improvements. 

The molecular model shown here represents acetamide, which is used as an organic solvent. Only the connections between the atoms are shown in this model. Draw two resonance structures for the molecule, showing the positions of multiple bonds and formal charges. (For color code, see inside back endpaper.)... 

The TOF velocity spectra show that the molecular weight of the CH3NHCHO product is -118, suggesting that this product leaves the reaction cell as a dimer. However, it is possible that this product has a structure that is somewhat different from N-methylformamide (e.g. acetamide). The two unique sets of products each have a mononitroso derivative of the parent compound. Experiments conducted under conditions in which RDX and HMX only evaporate and do not decompose show no evidence of the nitroso derivative, thus, this product is formed during the decomposition and is not a contaminant in the starting material. The other products that are unique to the RDX decomposition are NO2 and hydroxy-s-triazine (HST). These two products indicate that rupture of the N-N bond is an important reaction path way in RDX. The products that are unique to the decomposition of HMX are CO, C2H 20, and a nonvolatile residue (NVR). 

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