Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Hybrid orbitals boron and

Boron trifluoride and ethylene are but two of the many instances where the directional properties of covalent bonds are better described in terms of overlap of hybrid orbitals than in terms of simple atomic orbitals. [Pg.97]

Boron undergoes sp2 hybridization and forms three identical sp2 hybrid orbitals containing three unpaired electrons. Chlorine has 7 valence q B Q electrons of which just one of them is unpaired. Q  [Pg.30]

Orbitals are identified by their spontaneous symmetry relationships (<73 and its two symmetric counterparts resemble sp2 hybrids on boron, see Fig. 1). [Pg.293]

Boron trifluoride has a trigonal-planar structure. Formulate the bonding in terms of molecular orbitals for the Dsjj symmetry. In addition, construct wave functions for three equivalent sp2 hybrid orbitals, using the 2px, 2p, and 2s boron valence orbitals, which may be used to form three localized bonds with the three fluorines. Compare and contrast the molecular-orbital and the hybrid-orbital descriptions. [Pg.136]

It can be understood by formation of sp hybrid orbitals by Boron atom, one of these sp hybrid orbitals combines with H, Is, forming two M.O. (one bonding and one antibonding) and the second sp hybrid orbitals, which does not overlap much is non-bonding. [Pg.197]

The bonds are considered to arise from the combination of two boron orbitals that are hybrids of s and p orbitals with a b orbital on the hydrogen atom. Graphically, the formation of the three-center molecular orbital can be represented as shown here  [Pg.196]

Each B-H-B three-center two-electron bridge bond corresponds to a filled three-center localized bonding orbital requiring the hydrogen orbital and one hybrid orbital from each boron atom. [Pg.5]

Therefore, in order for boron to form a 77-bond perpendicular to the molecular plane to each of the chlorine atoms, it must use three hybrid orbitals constructed from one AO which belongs to V and a pair of AOs which belong to r Table 11-2.2 shows that only the following orbitals meet these requirements  [Pg.232]

Boranes, carboranes, and metallocarboranes are electron-deficient compounds in which B-H-B three-center two-electron (3c-2e) bridged bonds are found. The B-H-B bond results from the overlap of two boron sp3 hybrid orbitals and the Is orbital of the hydrogen atom, which will be discussed in Chapter 13. [Pg.401]

The planar framework has a bonds as just shown, which involve sp2 hybrid orbitals on the boron atoms. This leaves one unhybridized p orbital that is perpendicular to the plane. The B2H6 molecule can be considered being made by adding two H+ ions to a hypothetical B21142 ion that is isoelectronic with C2H4 because each carbon atom has one more electron than does a boron atom. In the B2I l42 ion, the two additional electrons reside in a tt bond that lies above and below the plane of the structure just shown. When two H+ ions are added, they become attached to the lobes of the n bond to produce a structure, the details of which can be shown as [Pg.126]

The electronic structure of the boron atom is 1 s2 2s2 Ip1. It might be expected that boron would lose the outer electrons and be present in compounds as B3+ ions. This ionization, however, requires more than 6700 kJ mol-1, and this amount of energy precludes compounds that are strictly ionic. Polar covalent bonds are much more likely, and the hybridization can be pictured as follows. Promoting a 2s electron to one of the vacant 2p orbitals can be accomplished followed by the hybridization to produce a set of sp2 hybrid orbitals  [Pg.191]

Examples of neutral Lewis acids are halides of group 3A elements, such as BF3. Boron trifluoride, a colorless gas, is an excellent Lewis acid because the boron atom in the trigonal planar BF3 molecule is surrounded by only six valence electrons (Figure 15.12). The boron atom uses three sp2 hybrid orbitals to bond to the three F atoms and has a vacant 2p valence orbital that can accept a share in a pair of electrons from a Lewis base, such as NH3. The Lewis acid and base sites are evident in electrostatic potential maps, which show the electron poor B atom (blue) and the electron rich N atom (red). In the product, called an acid-base adduct, the boron atom has acquired a stable octet of electrons. [Pg.647]

We can now go on to apply the same ideas to some other simple molecules. In boron trifluoride, for example, we start with the boron atom, which has three outer-shell electrons in its normal or ground state, and three fluorine atoms, each with seven outer electrons. As shown in the upper diagram, one of the three boron electrons is unpaired in the ground state. In order to explain the trivalent bonding of boron, we postulate that the atomic s- and p orbitals in the outer shell of boron mix to form three equivalent hybrid orbitals. These particular orbitals are called sp2 hybrids, meaning that this set of orbitals is derived from one s-orbital and two p-orbitals of the free atom. [Pg.41]

Exceptions Sometimes atoms break the octet rule. Molecules with such atoms include molecules with an odd number of electrons, molecules with an atom having less than an octet, and molecules with an atom having more than an octet. Compounds containing boron and beryllium may contain less than an octet. Molecules with an atom containing more than an octet must contain an atom from the third period or greater in the periodic table because only these a tours have vacant d orbitals available for hybridization. [Pg.2]


See other pages where Hybrid orbitals boron and is mentioned: [Pg.1275]    [Pg.250]    [Pg.38]    [Pg.28]    [Pg.57]    [Pg.262]    [Pg.124]    [Pg.255]    [Pg.7]    [Pg.1500]    [Pg.1500]    [Pg.195]    [Pg.20]    [Pg.424]    [Pg.427]    [Pg.124]    [Pg.309]    [Pg.444]    [Pg.271]    [Pg.57]    [Pg.10]    [Pg.8]    [Pg.261]    [Pg.262]    [Pg.288]    [Pg.94]    [Pg.648]    [Pg.823]    [Pg.278]    [Pg.278]    [Pg.300]    [Pg.469]    [Pg.297]    [Pg.306]    [Pg.192]    [Pg.195]    [Pg.234]   
See also in sourсe #XX -- [ Pg.33 ]




SEARCH



Boron 7 and

Boron hybridization

Hybrid orbital

Hybrid orbitals Hybridization

Orbital hybridization

Orbitals hybrid

Orbitals hybridization

Orbitals, hybridized

© 2019 chempedia.info