Groups I and II

These elements form two groups, often called the alkali (Group I) and alkaline earth (Group II) metals. Some of the physical properties usually associated with metals—hardness, high m.p. and b.p.—are noticeably lacking in these metals, but they all have a metallic appearance and are good electrical conductors. Table 6.1 gives some of the physical properties. 

From Table 6.1, it is easy to see that Group II metals are more dense, are harder and have higher m.p. and b.p. than the corresponding Group I metals. 

Element Atomic number Outer electrons Density (gem ) m.p. (K) h.p. IK) Hardness 1 Brineii) 

Element Ionisation energy (kj mof ) Metallic radius (nm) Ionic radius (nm) Heal oj laporibation at 298 K (kJ mol ) Hydration energy oj gaseous ion (kJ moI ) (V) 

lirM lonisaiion enerjjv. Be Bii Mini ol first and second ionisation enercies 

A full discussion of the changes in ionisation energy with group and period position has been given in Chapter 2. These data are given again in Table 6.2. 

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A further peculiarity of the Group I and II carbonates is the ability to form the hydrogencarbonate or bicarbonate ion HCOj ... 

These are halides formed by highly electropositive elements (for example those of Groups I and II, except for beryllium and lithium). They have ionic lattices, are non-volatile solids, and conduct when molten they are usually soluble in polar solvents in which they produce conducting solutions, indicating the presence of ions. 

Most of the acidic compounds containing only the elements C, H and O are either carboxylic acids or phenols. They are found mainly in Solubility Group III, although the water soluble members are in Solubility Groups I and II. 

Since tire alkali and alkaline metals have such a high affinity for oxygen, sulphur aird selenium they are potentially useful for the removal of these iron-metallic elements from liquid metals with a lower affinity for these elements. Since the hairdling of these Group I and II elements is hazardous on the industrial scale, their production by molten salt electrolysis during metal rehning is an attractive alternative. Ward and Hoar (1961) obtained almost complete removal of sulphur, selenium and tellurium from liquid copper by the electrolysis of molten BaCla between tire metal which functioned as the cathode, and a graphite anode. 

Two areas of passivity are located in Fig. 2-2 where Fe has a very low corrosion rate. In contrast to cathodically protected metals in groups I and II, the corrosion rate of anodically passivated metals in groups III and IV cannot in principle be zero. In most cases the systems belong to group IV where intensified weight loss corrosion or local corrosion occurs when U > U" There are only a few metals belonging to group III e.g., Ti, Zr [44] and A1 in neutral waters free of halides. 

The majority of the literature reports deal with the reaction of calixarenes with Group I and II cations. Polymeric calixarenes have been the subject of a more recent innovation. Harris et al. [23] have prepared a calix[4]ar-ene methacrylate, its polymerization, and Na complex-ation (Scheme 3). They concluded that both monomers and polymers form stable complexes with sodium thiocyanate. 

Coupling of alkyl halides with groups I and II organometallic... 

Despite possible electron-acceptor B sp combining with the group I and II main-group elements, only metastable AIB2 phases, AgB2 and AUB2, are known, and the Ag-B and Au-B systems exhibit simple monotectics and eutectics, respectively. 

Recently the ylide 16 or the corresponding protonated ligands allowed, in presence of metallated bases of groups I and II (Li, K, Ba), the synthesis of the first phosphonium bridged metallocene 17 (dicyclopentadienylide) (Scheme 12). Chiral kalocene and barocene, observed only in racemic forms, have thus been obtained [57]. 

What is the main difference in the use of quantum calculations between group I and II ... 

It is a reasonable activity for persons belonging to groups I and II to use, also for extensive applications, the tools they nave elaborated. This activity does not be confused, in my opinion, with that of members of group III. 

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