The features of electron deficient compounds Example a.forming coordination compound HBF HF→BF3 Example b.forming Al2Cl molecules in gas phase Al:ns2npl CK (sp3杂化) C:2s22p5
Cl Cl Al Cl Cl Cl Cl Al The features of electron deficient compounds Example b. forming Al2Cl6 molecules in gas phase HF BF3 Example a. forming coordination compound HBF4 Al：ns2np1 (sp3杂化) Cl：2s22p5
General properties of boron family elements ·Except for B which is a metalloid(非金属)，Al, Ga,In,Tl are all metals. Oxidation numbers:B,Al,Ga:(+3) In:(+1,+3) T1:(+1) Maximum coordination numbers: B:4 example:HBF4(sp3杂化) others:6 example:Na3AlF6(sp3d杂化)
General properties of boron family elements • Except for B which is a metalloid(非金属), Al， Ga，In，Tl are all metals. • Oxidation numbers：B，Al，Ga：(+3) In：(+1，+3) Tl：(+1) • Maximum coordination numbers： B：4 example：HBF4 (sp3杂化) others：6 example：Na3AlF6 (sp3d 2杂化)
13.2.2 The elemental substances of boron family 硼B metalloid 铝A1 netal 镓Ga metal 铟In metal
13.2.2 The elemental substances of boron family metalloid metal metal metal
The elemental substances of boron (denote B) Allotropes(同素异形体)：amorphous B-→brown powder (a few types)crystalline B->black-gray Properties:high chemical activity,high hardness high m.p and b.p a-菱形硼(B12)(one of the crystalline type of B): Atomic crystal 12 vertices,20 faces
The elemental substances of boron (denote B) Allotropes(同素异形体)：amorphous B → brown powder (a few types) crystalline B → black-gray Properties: high chemical activity, high hardness high m.p and b.p α-菱形硼 (B12) (one of the crystalline type of B): Atomic crystal 12 vertices, 20 faces
13.2.3 The compounds of boron 1.Boron hydrides (borane) General formula of boranes:BH4 and BHn+ Example:B2H B4H10。。。。o diborane borobutane H H No existence of BH3 B:2s22p H-BXB-H The simplest borane:B2H HH The structure of B,H cannot be depicted as the right figure:
13.2.3 The compounds of boron 1. Boron hydrides (borane) General formula of boranes: BnHn+4 and BnHn+6 Example： B2H6 B4H10。。。。。。 diborane borobutane 。。。。 No existence of BH3 The simplest borane：B2H6 The structure of B2H6 cannot be depicted as the right figure： H H B B H H H H B:2s22p1