Pseudo prefix

Identification of the position of substituents using the pseudo prefix, along with the cross and step descriptors, avoids the use of conflicting and potentially ambiguous nomenclatures [63]. 

EXTENSIONS AND COMMENT ARY Here is another example of the presentation of a compound for which there has not yet been an effective level determined. Why For a very good reason. This is an example of a whole class of compounds that I have called the pseudos, or the -compounds. Pseudo- as a prefix in the literary world generally stands for false. A pseudopod is a thing that looks like a foot, but isn t one. A pseudonym is a fictitious name. But in chemistry, it has quite a different meaning. If something has a common name, and there is a second form (or isomer, or shape, or orientation) that is possible and it doesn t have a common name, it can be given the name of the first form with a pseudo- attached. Ephedrine is the erythro-isomer of N-methyl-13-hydroxyamphetamine. There is a second stereoisomer, the threo- isomer, but it has no trivial name. So it is called pseudoephedrine, or the Sudafed of sinus decongestant fame. 

Here, there is the blatant, parallel call from TMA-6. It can serve, as the 2,4,6-counterpart, as a similar template compound. And the first indicators are that, in keeping the 2,6-dimethoxy aspect intact, a completely analogous series could be made, again with modifications of the 4-position. These have been named the psu-series, or psi-series, as an abbreviation for the prefix, pseudo, and can be differen-... 

Kim et al. discovered a method of reversibly fixing pseudorotaxane moieties to the outer shell by non-covalent interactions (Fig. 6.9). The prefix pseudo de-... 

A cp/mas VACP 13C-NMR study was made of these three pseudopolymorphic crystals (19, 21, and 22).29 The prefix pseudo is affixed to polymorph to describe this series of nefopam methohalide crystals since the anions therein are different. The results of this solid-state 13C-NMR study are presented in Table 3 along with the solution-state 13C chemical shifts. The cp/mas 13C-NMR spectra of crystalline 19, 21, and 22 are illustrated in Fig. 5. It is seen that the C(4) peak (<5 58.51) in the cp/mas 13C-NMR spectrum of the methochloride (22) is sharp due to the sole presence of the immobile BB conformation quaternary ammonium cation in the crystal. However, the C(4) peak (V) 59.42) in the methobromide (21) spectrum was markedly lower in intensity and broad, and in the methiodide (19) spectrum it was just a broad shoulder at 5 62.29 Therefore, as the C(4) nucleus becomes more site-disordered in the crystal due to conformational interconversion, its cp/mas peaks show lower intensities and greater line-broadening. 

McCrone (1965) also noted that second-order phase transitions have been termed as pseudopolymorphic. Such transitions are difficult to detect by optical methods, because of the small structural changes that occur hence, the origin of the prefix pseudo sometimes used to describe them. However, the birefringence of the crystals changes during such phase changes (see Section 4.2), so the use of crossed polarizers makes the phase change readily detectable. 

Pseudo.—A prefix of Greek origin indicating spurious or false. 

Some compounds contain polyatomic ions that behave much like monatomic anions. Compounds that contain these ions are called pseudobinary ionic compounds. The prefix pseudo- means false these compounds are named as though they were binary compounds. The common examples of such polyatomic anions are the hydroxide ion, OH , and the cyanide ion, CN. The ammonium ion, NH4+, is the common cation that behaves like a simple metal cation. 

The pseudo-Aristotelian Mechanical Problems is considered to be the first surviving ancient Greek text on mechanics (Coxhead 2012). The prefix pseudo is used because it is not certain if the book was actually authored by Aristotle or embodies... 

However, reaction (2.123) plays basically no role in natural waters with the exception of the initial state of cloud/fog droplet formation from alkahne CCN (e. g. flue ash and soil dust particles). The reaction rate constants (minus prefix means the inverse reaction) have been best estimated to be 2.i2o = 0.03 s" (25 °C) and -2.120 = 20 s (25 °C) as pseudo-first order rates and A 2.i23 = 8400 L mor s and k-2.m = 2 10 s . All K and k data given here are taken from Gmelin 1913) these data are also adapted by Sigg and Stumm 1996, Stumm and Morgan 1996). 

FIGURE 6.18 Radial pentagon for a pseudo 3-MCR [16]. The green aspect of this reaction is that it is a multicomponent reaction. It is designated with the prefix pseudo because two of the three reagents are identical. 

I o enhance the descriptive capabilities, plenty of neologisms are introduced, with various prefixes like quasi- , pseudo- , and even crypto-" (I), etc. 

As illustrated by consideration of 1-16, a number of modifiers are commonly used in the trivial nomenclature of furostanol saponins. Where an analogous spirostanol glycsoide has been reported previously with a trivial name, the prefix proto can be added to give the name of the furostanol, for example protodioscin (3) derived from dioscin (1). The methyl prefix is used to indicate that the glycoside is a C-22 methyl acetal (22-methoxy) furostanol (as in methylprotodioscin, (4)), while pseudo indicates -unsaturation... 

For the sake of clarity in the above scheme, the absolute configuration for one of the two possible enantiomeric syn- and anti-products is presented. Note that on the route to an anri-isomer both larger groups R and R are found in a pseudo-equatorial position in the cyclic transition state, present in the more stable chair conformation. In the transition state leading to the yn-isomer group R is found in the less preferred, crowded pseudo-axial position. Here we follow the suggestion to use the prefixes axial/equatorial only for substiments on the cyclohexane ring in the... 

If one now considers disubstituted Pc derivatives, particular descriptors are employed to designate the relation between the two positions. For substituents on the same phenyl ring, ortho, meta, and para prefixes are still valid, while inter-ring disubstitution gives rise to pseudo-gem, pseudo-ortho, pseudo-para, and pseudo-meta prefixes (Figure 8.3). Finally, a last remark about the configurational stability of Pc derivatives chiral [2.2]paracyclophanes can indeed racemize above 200°C by a process that was proven to involve benzylic-bond homolytic scission, rotation, and recombination of the diradical. 

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