Temperature reactions and trapped by chilling to liquid nitrogen temperatures. Thus at ca. 1100° and low pressures, the following reaction gose in ca.95.5% yield
สมการ
SiF2 is stable for a few minutes at 10-4 cm pressure; the molecule is angular and diamagnetic. When the frozen compound warms, it gives fluorosilanes up to SiF16F34.
Germanium. Germanium dihalides are stable. GeF2 is a white crystalline solid obtained by action of anhydrous HF on Ge at 200°; it is a fluorine bridged polymer with approximately tbp coordination of Ge. GeCl2
Give salts of the GeCl3- ion similar to those of Sn noted below.
Tin. The most important compounds are SnF2 and SnCl2, which are obtained by heating Sn with gaseous HF or HCl. The fluoride is sparingly soluble in water and is used in fluoride-containing toothpastes. Water hydrolyzes SnCl2 to a basic chloride, but from dilute acid solutions SnCl2∙ 2H2O can crystallized. Both halides dissolve in solutions containing an excess of halide ion, thus:
สมการ
In aqueous fluoride solutions SnF3- is the major species, but the ions SnF+ and Sn2F6- can be detected.
The halides dissolve in donor solvents such as acetone, pyridine, or DMSO, to give pyramidal adducts, for example, SnCl2OC (CH3)2.
The very air-sensitive stannous ion, Sn2+, occurs in acid perchlorate solutions, which may be obtained by rection
Cu(Cl4)2 + Sn/Hg = Cu + Sn2+ + 2Cl4-
Hydrolysis gives [Sn3(OH)4]2+ ,with SnOH+ and [Sn2(OH)4]2+ in minor amounts:
สมการ
The trimeric, probably cyclic, ion appears to provide the nucleus of several basic tin(II) salts obtained from aqueous solutions at fairly low PH. Thus the nitrate appears to be Sn3(OH)4(NO3)2OSO4.All SnII solutions are readily oxidized by oxygen and, unless stringently protected from air, normally contain some SnIV. The chloride solutions are often used as mild reducing agents:
สมการ
Lead. Of the four elements, only lead has a well-defined cationic chemistry.
The plumbous ion, Pb2+ is partially hydrolyzed in water. In perchlorate solution
สมการ
Temperature reactions and trapped by chilling to liquid nitrogen temperatures. Thus at ca. 1100° and low pressures, the following reaction gose in ca.95.5% yield
สมการ
SiF2 is stable for a few minutes at 10-4 cm pressure; the molecule is angular and diamagnetic. When the frozen compound warms, it gives fluorosilanes up to SiF16F34.
Germanium. Germanium dihalides are stable. GeF2 is a white crystalline solid obtained by action of anhydrous HF on Ge at 200°; it is a fluorine bridged polymer with approximately tbp coordination of Ge. GeCl2
Give salts of the GeCl3- ion similar to those of Sn noted below.
Tin. The most important compounds are SnF2 and SnCl2, which are obtained by heating Sn with gaseous HF or HCl. The fluoride is sparingly soluble in water and is used in fluoride-containing toothpastes. Water hydrolyzes SnCl2 to a basic chloride, but from dilute acid solutions SnCl2∙ 2H2O can crystallized. Both halides dissolve in solutions containing an excess of halide ion, thus:
สมการ
In aqueous fluoride solutions SnF3- is the major species, but the ions SnF+ and Sn2F6- can be detected.
The halides dissolve in donor solvents such as acetone, pyridine, or DMSO, to give pyramidal adducts, for example, SnCl2OC (CH3)2.
The very air-sensitive stannous ion, Sn2+, occurs in acid perchlorate solutions, which may be obtained by rection
Cu(Cl4)2 + Sn/Hg = Cu + Sn2+ + 2Cl4-
Hydrolysis gives [Sn3(OH)4]2+ ,with SnOH+ and [Sn2(OH)4]2+ in minor amounts:
สมการ
The trimeric, probably cyclic, ion appears to provide the nucleus of several basic tin(II) salts obtained from aqueous solutions at fairly low PH. Thus the nitrate appears to be Sn3(OH)4(NO3)2OSO4.All SnII solutions are readily oxidized by oxygen and, unless stringently protected from air, normally contain some SnIV. The chloride solutions are often used as mild reducing agents:
สมการ
Lead. Of the four elements, only lead has a well-defined cationic chemistry.
The plumbous ion, Pb2+ is partially hydrolyzed in water. In perchlorate solution
สมการ
การแปล กรุณารอสักครู่..
