Cations naming

Substituted ammonium ions derived from nitrogen bases with names ending in -amine receive names formed by changing -amine into -ammonium. When known by a name not ending in -amine, the cation name is formed by adding the ending -ium to the name of the base (eliding the final vowel) e.g., anilinium, hydrazinium, imidazolium, acetonium, dioxanium. 

As mentioned at the end of Section 8.3, the MO investigation by Apeloig and Arad (1985) of the influence of trimethylsilyl substituents on the phenyl cation led to the discovery of a further reagent, in addition to arenediazonium ions, that is able to form aryl cations, namely 2,6-bis-(trimethylsilyl)phenyltriflate. This was a significant success in the field of predictions on aryl cations by theoretical work. 

An ionic compound is named with the cation name first, followed by the name of the anion the word ion is omitted in each case. The oxidation number of the cation is given if more than one charge is possible. However, if the cation comes from an element that exists in only one charge state (as listed in Fig. C.6), then the oxidation number is omitted. Typical names include potassium chloride (KC1), a compound containing K+ and Cl" ions and ammonium nitrate (NH4NOs), which contains NH4+ and NO3" ions. The cobalt chloride that contains Co2+ ions (CoCl,) is called cobalt(II) chloride C0CI3 contains Co3+ ions and is called cobalt(III) chloride. 

The name of a coordination compound (as distinct from a complex cation or anion) is built in the same way as that of a simple compound, with the cation named before the anion ... 

Calculation of the second-order rate constant of carbonylation, kg, and the equilibrium constant, K = [t-C4H9CO+]/[t-C4H ][CO] = A c/fcD> requires knowledge of the concentration of CO. The constant a in Henry s law Pco = [CO] was determined to be 5-3 litre mole atm in HF—SbFs (equimolar) and 53 litre mole atm in FHSOs—SbFs (equimolar) at 20°C. From the ratio [t-C4HBCO+]/[t-C4HJ"] at a known CO pressure, values for k and K were obtained. The data are listed in Table 1, which includes the values for the rate and equilibrium constants of two other tertiary alkyl cations, namely the t-pentyl and the t-adamantyl ions (Hogeveen et al., 1970). 

Ionic compounds are named using the same guidelines used for naming binary molecules, except that the cation name aiways precedes the anion name. Thus, NH4 NO3 is ammonium nitrate, Na2 CO3 is sodium carbonate, and Ca3 (P04)2 is caicium phosphate. The subscripts are not specified in these names because the fixed ionic charges determine the cation-anion ratios unambiguously. Example 3-6 reinforces these guidelines by showing how to construct chemicai formulas from chemical names. 

Cr03 As a transition metal, chromium forms more than one stable cation. Name the metal first, using a Roman numeral to designate chromium s charge. Each of the three oxide anions has a -2 charge. To maintain net charge neutrality, Cr must be +6, so the name of the compound is chromium(VI) oxide. 

Compounds which have low IP and sufficient charge localization in the radical cation, namely 7-methylbenz[a]anthracene, BP,... 

Chronologically, Sato and coworkers have been the first to obtain and to characterized unambiguously a fractional oxidation state compound containing the Ni (dmit)2 unit and an SCO cation, namely [Fe(qsal)2][Ni(dmit)2]3.CH3CN.H20 [106]. This complex has been obtained after electrocrystallization from an acetonitrile solution of [Fe(qsal)2][Ni(dmit)2].2CH3CN. 

A The name of each of these ionic compounds is the name of the cation followed by that of the anion. Each anion name is a modified (with the ending ide ) version of the name of the element. Each cation name is the name of the metal, with the oxidation state appended in Roman numerals in parentheses if there is more than one type of cation for that metal. 

Ammonium salts contain a nitrogen atom with four bonds that has a positive charge. Four-bonded nitrogen atoms derived from amines are ammonium ions (if they re derived from aniline, they re anilinium ions). If the four bonds are all to carbon atoms, the nitrogen atom is quaternary. Salts contain a cation (named first) and an anion (named last). Typical anions include Cl (chloride), Bi" (bromide), HSO (hydrogen sulfate or bisulfate), and NOj-(nitrate). Figure 13-5 shows two examples of ammonium ions. 

The symbols (formulae) are listed in alphabetical order according to the principles outlined above. Because the terminations -ous and -ic for metal cation names are no longer recommended, these have been excluded, but we have attempted to include all those traditional names that are still allowed. We have not attempted to present names for species of very rare or unlikely occurrence, so there are gaps in the columns. 

Classification of Solvents in Terms of Specific Solute-Solvent Interactions Parker divided solvents into two groups according to their specific interactions with anions and cations, namely dipolar aprotic solvents and protic solvents (Parker, 1969). The distinction lies principally in the dipolarity of the solvent molecules and their ability to form hydrogen bonds. It appears appropriate to add to these two groups a third one, namely, the apolar aprotic solvents. 

These compounds are all ordinciry ionic compounds, so you simply need to pair the cation name with the anion name and change the anion name s ending to -ide. 

We may perform the same analysis for the allyl radical and the allyl anion, respectively, by adding the energy of 4>2 to the cation with each successive addition of an electron, i.e., H (allyl radical) = 2(a + V2/3) + a and Hn allyl anion) = 2(a + s/2f) + 2a. In the hypothetical fully 7T-localized non-interacting system, each new electron would go into the non-interacting p orbital, also contributing each time a factor of a to the energy (by definition of o ). Thus, the Hiickel resonance energies of the allyl radical and the allyl anion are the same as for the allyl cation, namely, 0.83/1. 

Electropositive condiments. The name of a monoatomic electropositive constituent is simply the unmodified element name. A polyatomic constituent assumes the usual cation name, but certain well established radical names (particularly for oxygen-containing species such as nitrosyl and phosphoryl) are still allowed for specific cases... 

Coordination cations. The names of complex cations are derived most simply by using the coordination cation names (see Section I—10). This is preferred whenever umbigu-ity might result. 

Because of the similar energy of the two possible resonances that can ensure hydration of the pteridine cation (namely, 4-aminopyridinium stabilization of 7,8-hydration and amidinium stabilization of 3,4-hydration3 ), a study of the effects of substituents on this delicately balanced system was undertaken. An initial survey showed that the majority of pteridine cations were subject neither to dihydration nor to shifting hydration. Only four examples were found in which 5,6,7,8-dihydration was preceded by 3,4-hydration, namely 2-methyl-, 6-methyl-, 7-methyl-, and 2-amino-4-methylpteridine, whereas the related cations of 6,7-dimethyl-, 2-amino-, 2-amino-6-methyl-, and 2-amino-7-methylpteridine remained stably hydrated in the 3,4-position.8,40 Further examples, including a reversed direction of shift, came to light from a... 

IUPAC Rules B-6 and B-10 give examples of heterocyclic cations named by replacement principles. The normal replacement prefixes... 

If the transition metal forms only one cation, you name it like a representative metal cation name the element and call it a cation. If the transition metal forms more than one cation, you need to name the metal and then indicate the charge on the cation with Roman numerals in parentheses. 

E ) to 32 M 1 (I ). However, when the counter cations were switched to l-phenylalanine methyl ester (H3N+CH(Bn)C02Me), these and other anion affinities were found to increase by an order of 103 M 1. It should be noted, however, that the inherent anion selectivities remained the same with both counter cations, namely N03 >CI >CE3C02 > Br sTsO->l. Ah initio calculations supported the assumption that the binding of both the anion and the cation was cooperative. 

The layer charges (X ) of montmorillonite are neutralized by cations, namely, sodium or calcium ions in natural minerals or any other cations in cation-ex-changed montmorillonites. As our model substance is calcium-montmorillonite, the neutralization of the layer charge can be described as follows ... 

Bromocomplexes of plutonium are limited in number tri- and tetravalent complexes with organic cations, namely C(C6 5)3P l3 PuBrg(c) (70) and [(C2H5)4N]2 PuBr5(c) (71) have been reported. Also, adducts of the type PuBr. 2L (with L = hexamethylphosphora-mide and tri phenyl phosphine oxide) are known (72.). No thermodynamic information are available on these species. More recently, however, the compound Cs2PuBr5(c) has been prepared (63) and its enthalpy of solution in 1 M HCl was measured as - 75.3 + 0.21 kJ. mol l. This measurement leads to a value of AHS(Cs2PuBr, c) =... 

A similar encapsulated dinuclear species was prepared by Warzeska and Kramer (80) who employed a polyaza macrocycle XX to preorganize u(II) ions for a cyanide bridging interaction. The product obtained upon treating a solution of [ u 2(XX)(Me N)2](OTf)4 with cyanide and subsequent addition of aperchlorate salt contains two separate dinuclear cations, namely [ u°2(XX)( N)(Me N)2] and [ u 2(XX)( N)(H20)2], cocrystaUized with six 104 anions. In both cations, each u(II) ion is in an elongated octahedral environment of the... 

The decrease of the contribution from the diffusion potential with increasing N can be explained as follows. For large N, that is, for the case where the surface layers are highly negatively charged, colons (i.e., anions) are repelled by the membrane so that the membrane is in practice impermeable to coions and their flow within the membrane, J, decreases. Since the net electric current must be zero (/+ — / =0), the flow of counterions (i.e., cations), 7+, must decrease to the same extent as J. That is, all ionic flows decrease, resulting in a smaller diffusion potential. In the limit of A oo, the membrane becomes fully impermeable to anions and an equilibrium is reached with respect to cations so that the membrane potential tends to the Nemst potential for cations, namely. 

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