Proposed structure

In the mid-nineteenth century, the empirical formula of benzene, was known but its structural formula was tiot. Two proposed structures... 

In 1967 he again wrote, The second subclass consists of ions such as the bicyclobutonium and the norbornyl cation in its cr-bridging form, which do not possess sufficient electrons to provide a pair for all of the bonds required by the proposed structures. A new bonding concept not yet established in carbon structures is required (emphasis added). 

Nucleophilic addition of 2-aminothiazole to the double bond of di-maleic acid hydrazine has been reported (206). No spectroscopic proof, however, is given to establish the proposed structure (60) for the resulting product (Scheme 41). 

The benzodiazepine fused azetes (353 R = Et, Pr) have been claimed as useful tranquilizers and sedatives (76BRP1448895). However, their stability and formation from benzodiazepines (352) by reaction with an aldehyde and base is hard to reconcile with the proposed structure. 

These genetic experiments clearly demonstrated that the proposed structural model for the binding of these proteins to the phage operators was essentially correct. The second a helix in the helix-turn-helix motif is involved in recognizing operator sites as well as in the differential selection of operators by P22 Cro and repressor proteins. However, a note of caution is needed many other early models of DNA-protein interactions proved to be misleading, if not wrong. Modeling techniques are more sophisticated today but are still not infallible and are certainly not replacements for experimental determinations of structure. 

Fig. 12. As-grown PCNTs with partially thickened spindle shape (a) and the proposed structural model for spindle particles including 12 pentagons in hexagon cage (b).

At ceremonies in Berlin in 1890 celebrating the twenty-fifth anniversary of his proposed structure of benzene, August Kekule recalled the origins of his view of the benzene structure. 

FIGURE 21.6 Proposed structure and electron transport pathway for Complex I. 

The chloride can be crystallized but the bromide disproportionates. On the basis of mol wt and infrared spectroscopic evidence the proposed structure is ... 

Proposed structure of Bi4H , omitting Teiminal hydrogen atoms have been omilled terminal hydrogen atoms for clarity for clarity... 

Figure 13.19 Proposed structures for (a) the tridentate cycZo-polyarsane complex [Cr(CO)3(As5Mes)], and (b) the bismonodentate binuclear complex [ Cr(CO)sl2(As5Me5)].

These early contradictions were eventually resolved and led to the correction by Knorr of his initially proposed structure. While Conrad and Limpach described the reaction of aniline 1 with ethyl acetoacetate 5 which ultimately yielded 4-hydroxy-2-methylquinoline (7) via initial reaction of the amine with the ketone, Knorr described... 

The proposed structure of 97 isolated from broiled sardines was confirmed by straightforward synthesis starting from5,6-diaminoquinolines. After reaction with cyanogen bromide it afforded the 2-amino-imidazo[4,5-/]quinolines 99 (R = H, Me), which was then converted into its 3-A-methyl derivative 100 by... 

The synthesis leading to the originally proposed structure 120 starts from Oxychelerythrine (124) as shown in Scheme 45 (85CPB1763). The structure is not identical to the naturally occurring compounds and obviously does not occur in nature. 

This compound was prepared by Allen et who found it to be monobasic and to form a simple methiodide. Attempted Hofmann degradation of this methiodide failed to give any information. The dimer was found to be perfectly stable to hot aqueous sulfuric acid. With the foregoing data, and by analogy with the alkyl pyrrole dimers, they proposed structure (9) for the dimer. Later work confirmed this structure by conversion via the methiodide into base (10) which was synthesized by way of the metho salt (11), isomeric with... 

Mainly based on the failure of 2-methylindole to form a dimer, Schmitz-DuMont proposed structure (24) for indole dimer, the argument being that a methyl group in position 2 would effectively hinder the formation of a skeleton of type (24), whereas one in position 3 would not. ... 

Fig. 2-1 Proposed structures of three macrocycUc glycopeptides. On teicoplanin, R = 8-methyl-nonanoic acid.

Figure 8 (a) Schematic diagram showing distribution of fillers in different parts of anionic elastomer [27]. (b) Proposed structural model showing interaction of silanol groups on silica surface with carboxylale groups [27]. 

Fig. 5. A proposed structure for 1 1 complex of [18]aneN6 3 H + with ATP at neutral pH 431...

Propose structures for molecules that meet the following descriptions ... 

Propose structures for simple molecules that contain the following functional groups ... 

Propose structures for two isomers with the formula C2H7N. 

Propose structures and give IUPAC names for the following ... 

Propose structures for alkenes that yield the following products on reaction with ozone followed by treatment with Zn ... 

Hydrocarbon A has the formula C9HI2 and absorbs 3 equivalents of H to yield B, C9H]g, when hydrogenated over a Pd/C catalyst. On treatment of A with aqueous H2S04 in the presence of mercury(d), two isomeric ketones, C and D, are produced. Oxidation of A with KMn04 gives a mixture of acetic acid (CH3C02H) and the tricarboxylic acid E. Propose structures for compounds A-D, and write the reactions. 

Propose structures for hydrocarbons that give the following products on oxidative cleavage by KMnOj or 03 ... 

---