Survey of structures

5 Ring Carbonyl Compounds and their Hydroxy Tautomers 3.3.2.5.1 Survey of structures 

Hydroxy derivatives of thiophene, pyrrole and furan (240 and 243) are tautomeric with alternative non-aromatic carbonyl forms (241, 242 and 244), as discussed in Section 2.3.5.2. 

In the majority of cases, the equilibrium lies predominantly in favor of the carbonyl tautomer, and for this reason these compounds are considered in the present section. (Most amino and mercapto analogues, while also tautomeric, exist predominantly as such, and they are therefore considered as substituted aromatic compounds.) 

Compounds of types (245) and (246) bear a formal structural resemblance to quinones but little similarity in properties this can be ascribed to the lower aromaticity of the parent heterocyclic systems. 

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G. Heller, Topics in Current Chemistry No. 131 Springer-Verlag, Berlin, 1986, 39-98 (a survey of structural types with 568 refs.). 

Molybdenum enzymes a survey of structural information from EXAFS and EPR spectroscopy. S. P. Cramer, Adv. Inorg. Bioinorg. Mech., 1983, 2, 260 (137). 

Heller, G. A Survey of Structural Types of Borates and Polyborates. 131, 39-98 (1985). 

Ostuni E, Chapman RG, Holmlin RE, Takayama S, Whitesides GM (2001) A survey of structure-property relationships of surfaces that resist the adsorption of protein. Langmuir 17 5605... 

Taft and coworkers106a, have recently reviewed the substituent and structural effects in a comprehensive analysis of substituents constants1063, followed by a survey of structural effects in organic chemistry1066. 

To complete our survey of structurally-characterized oxide-bridged Mn complexes, we describe species with nuclearities >4. Three distinct types have been reported hexanuclear, nonanuclear and dodecanuclear. The hexanuclear complex Mn602(piv)10(pivH)4 results from the treatment of MnC03 with pivalic acid in reflux-... 

Heller, G. 1986. A survey of structural types of borates and polyborates. Pages 39-100 in P.L. Boschke (ed.). Structural Chemistry of Boron arul Silicon. Springer-Verlag, Berlin. 

Because of the diverse nature of the ring systems comprising this chapter, a systematic treatment of their spectral properties is impossible, and therefore only a brief survey of structurally significant properties is included. It is no coincidence that the most thoroughly studied systems are those which contain unusual structural units such as the —N=S=N— group. 

The topic of low-barrier hydrogen bonds (LBHBs) and the question of how they are involved in enzyme function has been discussed heavily in the literature recently. Hydrogen bonds between two bases of nearly matched proton affinity often exhibit strongly perturbed bond lengths and spectroscopic parameters it remains somewhat unclear exactly how the spectroscopic parameters reflect total energy or reactivity. In this study, we report H NMR chemical shift data and surveys of structural preferences for the well-studied 0-H---0 systems, and also for less studied, but biologically important N-H-0 systems, in particular the imidazole and imidazolium functionality. The H shifts also show interesting trends in comparison with O-H-O motifs, which will require further scrutiny. 

Following the identification of 1, a survey of structurally related compounds from the company collection led to the identification of compound 15 (Figure 11.12). Binding of this compound to BACE could be detected by NMR spectroscopy, but could not be quantitated by SPR spectroscopy. Although the affinity was very weak, the compound was of interest because the nonaromatic nature of the heterocycle made the overall structure significantly different from that of the isocytosines. Despite the weak affinity, it could be crystallized... 

Ostuni, E., Chapman, R. G., Holmlin, R. E., Takayama, S. Whitesides, G. M. A Survey of Structure-Property Relationships of Surfaces that Resist the Adsorption of Protein. Langmuir 17, 5605-5620 (2001). 

Moeller, T. (1982). Inorganic Chemistry A Modem Introduction. New York John Wiley. Chapter 7 includes a good survey of structures, nomenclature, and isomerism. 

A Survey of Structural Types of Boratre and Poly borates Mg2[B205] H2O = Mg2(0H)[B204(0H)] = mme,r szaibelyite(iorTaetascharite) ... 

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