Sp hybrid bonds

Here, the bonding between carbon atoms is briefly reviewed fuller accounts can be found in many standard chemistry textbooks, e.g., [1]. The carbon atom [ground state electronic configuration (ls )(2s 2px2py)] can form sp sp and sp hybrid bonds as a result of promotion and hybridisation. There are four equivalent 2sp hybrid orbitals that are tetrahedrally oriented about the carbon atom and can form four equivalent tetrahedral a bonds by overlap with orbitals of other atoms. An example is the molecule ethane, CjH, where a Csp -Csp (or C-C) a bond is formed between two C atoms by overlap of sp orbitals, and three Csp -Hls a bonds are formed on each C atom. Fig. 1, Al. 

In cinnabar, HgS, the sulfur atom has a normal-valence structure, in which it forms two bonds with mercury atoms. The Hg—S—Hg bond angle is 105°. The mercury atom may be described as forming two oppositely directed bonds with use of two sp hybrid bond orbitals the value of the S—Hg—S angle is 172°. The bond length, 2.36 A, leads,... 

Diamondoids are hydrogen-terminated nanodiamonds with sp hybrid bonding between the carbon atoms. The smallest of these hydrogenated nanodiamonds is adamantane (Figs. 4.3b and 4.5). 

The free valence electron pairs on the central atom seek high -character i.e., sp" hybridization. If the number of ligands is larger than 4 and one or more of them are free valence election pairs, then as many F ligands form linear semi-ionic 3 center-4 electron bonds as are required to allow the free electron pairs to form an sp" hybrid with the remaining F ligands. These semi-ionic 3c-4e bonds are considerably weaker and longer than the mainly covalent sp hybrid bonds. 

Which of the molecules has four sp hybrid bonds B. amine... 

C60 has not yet been detected in primitive meteorites, a finding that could demonstrate its existence in the early solar nebular or as a component of presolar dust. However, other allotropes of carbon, diamond and graphite, have been isolated from numerous chondritic samples. Studies of the isotopic composition and trace element content and these forms of carbon suggest that they condensed in circumstellar environments. Diamond may also have been produced in the early solar nebula and meteorite parent bodies by both low-temperature-low-pressure processes and shock events. Evidence for the occurrence of another carbon allotrope, with sp hybridized bonding, commonly known as carbyne, is presented. 

A nitrile is a compound containing the cyano group, — C=N. The cyano group was introduced in Section 2-6 as an example of sp hybridized bonding. The cyano group is strongly polar by virtue of the Ctriple bond, and most small nitriles are somewhat soluble in water. Acetonitrile is miscible with water. 

We assume here that since two geometrically equivalent bonds are formed by each carbon, this atom must be sp-hybridized in acetylene. On each carbon, one sp hybrid bonds to a hydrogen and the other bonds to the other carbon atom, forming the c bond skeleton of the molecule. 

Silicon and germanium are the most important elemental semiconductors. They have the diamond cubic structure with sp hybrid bonds. The structure of the low index crystallographic planes, the only ones to be considered here, is shown in Fig. 1. It is seen that in the ill surfaces the atoms are triply bonded to the layer below and thus have one unpaired electron (dangling bond). Each atom of the 110 surfaces also... 

Comparison of the elements of the third and fifth groups, both having three unpaired electrons leads to an explanation of their stereochemistry. Boron has one s and two p electrons and thus forms three planar sp hybrid bonds, whereas nitrogen possesses three p electrons which form bonds at right angles to each other. The comparison is similar between elements of the sixth group and beryllium, in the former case the unpaired electrons are p electrons thus forming two bonds at 90°, whilst beryllium with one s and one p electron forms two linear sp hybrid bonds. 

In silica and the silicates, each atom of silicon is surrounded tetrahedrally by four atoms of oxygen. This structure is in agreement with the tetra-valency of silicon and with the directional character of the four sp hybrid bonds. In such an SiO group, only one of the two valencies of oxygen... 

The sp hybridized bonds are linear, ruling out cis-trans isomers in which substituents must be on different sides of the multiple bond. 

The s character of the vinylic C-H bond of cyclopropene is midway between that of sp and sp hybridized bonds and some similarity in behaviour to the acetylenic C—H bond is noted, particularly with regard to the acidity of the proton. Molecular orbital calculations at the ab initio level support an enhanced acidity of C(l)-H over C(3)-H in cyclopropene and correctly predict the preference for a 1-lithio derivative. A bis-lithio derivative is expected to have both lithium atoms bridging the C(l)-C(2) a bond. 

Db-b values not corrected for steric strain in the A4 molecules. The bond energies of the spS hybridized bonds will be a few percent higher. 

The combination of sp , sp and sp hybridized atoms can give rise to a large number of carbon allotropic forms and phases, but only carbon solids based on all sp (diamond) and sp (graphite, fullerene) hybridization are well known and characterized [1]. In addition there are innumerable transitional forms of carbon where sp and sp hybridization bonds co-exist in the same... 

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