Silicon

等等。

目錄

[

隱藏

]

1

矽烷化學式列表

?

2

製備

?

3

應用

?

4

參考資料

?

[

編輯

]

矽烷化學式列表

下面是前

種直鏈烷烴的

分子式

和結構模型圖。

碳數

名稱

分子式

結構圖

1

甲矽烷

SiH

4

2

乙矽烷

Si

2

H

6< /p>

3

丙矽烷

Si

3

H

8

正

丁矽烷

S i

4

H

10

正

戊矽烷

Si

5

H

12

正

己矽烷

S i

6

H

14

正

庚矽烷

Si

7

H

16

4

5

6

7

8

正

辛矽烷

S i

8

H

18

9

正

壬矽烷

S i

9

H

20

10

正

癸矽烷

S i

10

H

22

[

編輯

]

製備

工業上，多晶塊狀

冶金

級矽首先在攝氏

200

度置於

流床

反應器下

鹽酸化

鹽酸

氣形成

三氯化矽

和

氫氣

。反應

式如下：

Si + 3 HCl → HSiCl

3

+ H

2

將經 過

蒸餾

純化的三氯化矽置於有

催化劑< /p>

的

resinous bed

反應器而產 生

歧化反應

，形成矽烷和

四氯化矽

。反應式如下：

4 HSiCl

3

→

SiH

4

+ 3 SiCl

4

此反應的催化劑常以

金屬鹵化物

爲主，尤其是

氯化鋁

。

[

編輯

]

應用

矽烷在醫學和工業領域有著廣泛的應用。例如，矽烷

ar

[

編輯

]

參考資料

organofunctional silanes from Degussa AG

?

organofunctional silanes for building protection - water repellents - masonry protection - Graffiti Controll - sealer - easy to

clean surface from Degussa AG

?

chlorosilanes for telecommunication and electronic materials from Degussa

?

以矽烷化合物製備多晶矽原料

取自

/wiki/%E7%A1%85%E 7%83%B7

?

2

個分類

:

矽化合物

|

氫化物

Silane

From Wikipedia, the free encyclopedia

Jump to:

navigation

,

search

Silane

IUPAC

name

Silane

Silicon tetrahydride

Silicon hydride

Other names

Monosilane

Silicane

Identifiers

CAS

number

[7803-62-5]

UN number

2203

RTECS

number

VV1400000

Properties

Molecular

formula

SiH

4

Molar mass

32.12 g mol

?

1

Appearance

Colorless gas

Density

Melting

? kg m

?

3

(solid)

0.7 g/ml (liquid)

1.342 g L

?

1

(gas)

88 K (?185°C)

point

Boiling

point

161 K (?112°C)

Solubility

in

Insoluble

water

Structure

Molecular

shape

Dipole

moment

tetrahedral

0

D

Thermochemistry

Std enthalpy

of

-1615 kJ mol

?

1

formation

Δ

f

H

o

298

Standard

molar

283 J mol

?

1

K

?

1

entropy

S

o

298

Hazards

low toxicity,

avoid exposure to skin,

irritant, may cause

redness and swelling,

extremely flammable,

pyrophoric

NFPA 704

Main

hazards

4

1

3

Flash point

N/A

Autoignition

294 K (21°

C)

temperature

Related compounds

Related

hydrides

methane

Related

disilene

compounds

Except where noted otherwise, data are

given for

materials in their

standard state

(at 25 °

C, 100 kPa)

Infobox references

Silane

is a

chemical compound

with

chemical formula

SiH

4

. It is the

silicon

analogue

of

methane

. At

room temperature

, silane is a gas, and

is

pyrophoric

—

it undergoes spontaneous

combustion

in

air

, without the need for external ignition.

[1]

However, the difficulties in explaining

the available (often contradictory) combustion data are ascribed to the fact that silane itself is stable and that the natural formation of larger

silanes during production, as well as the sensitivity of combustion to impurities such as moisture and to the catalytic effects of container

surfaces causes its pyrophoricity.

[2][3]

Above 420°C, silane decomposes into silicon and

hydrogen

; it can therefore be used in the

chemical

vapor deposition

of silicon.

More generally, a silane is any silicon analogue of an

alkane

hydrocarbon. Silanes consist of a chain of silicon atoms

covalently bound

to

hydrogen atoms. The general formula of a silane is Si

n

H

2 n+2

. Silanes tend to be less stable than their carbon analogues because the Si

–

Si

bond

has a strength slightly lower than the C

–

C bond.

Oxygen

decomposes silanes easily, because the silicon-oxygen bond is quite

stable.

There exists a regular nomenclature for silanes. Each silane's name is the word silane preceded by a numerical prefix (di, tri, tetra, etc.) for

the number of silicon atoms in the molecule. Thus Si

2

H

6

is

disilane

, Si

3

H

8

is trisilane, and so forth. There is no need for a prefix for one;

SiH

4

is simply silane. Silanes can also be named like any other inorganic compound; in this naming system, silane is named silicon

tetrahydride. However, with longer silanes, this becomes cumbersome.

A

cyclosilane

is a silane in a ring, just as a

cycloalkane

is an alkane in a ring.

Branched silanes are possible. The

radical

·SiH

3

is termed silyl, ·Si

2

H

5

is disilanyl, and so on. Trisilane with a silyl group attached to the

middle silicon is named silyltrisilane. The nomenclature parallels that of

alkyl

radicals.

Silanes can also incorporate the same functional groups as alkanes, e.g.

–

OH

to make a

silanol

. There is (at least in principle) a silicon

analogue for all carbon alkanes.

Contents

[

hide

]

?

?

?

?

?

?

1 Production

2 Properties

3 Applications

4 Safety and precautions

5 See also

6 References

[

edit

] Production

Industrially, silane is produced from metallurgical grade silicon in a two-step process. In the first step, powdered silicon is reacted with

hydrogen chloride

at about 300°C to produce

trichlorosilane

, HSiCl

3

, along with

hydrogen

gas, according to the

chemical equation

:

Si + 3HCl → HSiCl

3

+ H

2

The trichlorosilane is then boiled on a

resinous

bed containing a

catalyst

which promotes its

disproportionation

to silane and

silicon

tetrachloride

according to the chemical equation:

4HSiCl

3

→ SiH

4

+ 3SiCl

4

The most commonly used catalysts for this process are

metal

halides

, particularly

aluminium chloride

.

For classroom demonstrations, silane can be produced (temporarily) by heating

sand

with

magnesium

powder, then pouring the mixture

into a 20%

dilution

of hydrochloric acid. The magnesium silicide reacts with the acid to produce silane gas, which combusts on contact with

air and produces tiny explosions.

[4]

[

edit

] Properties

Silane has a repulsive smell.

[5]

Silane has recently been shown to act as superconductor under extremely high pressures (96 and 120 GPa), with a transition temperature

of 17 K.

[6]

Unfortunately, there was briefly an EE Times article that grossly exaggerated this achievement and claimed that

room-temperature superconductivity had been achieved.

[

edit

] Applications

Several industrial and medical applications exist for silane and functionalized silanes. For instance, silanes are used as coupling agents to

adhere

glass fibers

to a

polymer

matrix, stabilizing the

composite material

. They can also be used to couple a bio-inert layer on a

titanium

implant

. Other applications include water repellents,

masonry

protection, control of

graffiti

,

[7]

applying

polycrystalline silicon

layers on

silicon wafers when manufacturing semiconductors, and sealants. Semiconductor industry alone used about 300

metric tons

per year of

silane in the late 1990s.

[3]

More recently, a growth in low-cost

solar panel

manufacturing has lead to substantial consumption of silane for

depositing

amorphous silicon

on glass and other surfaces.

Silane is also used in

supersonic combustion ramjets

to initiate combustion in the compressed air stream.

Silane and similar compounds containing Si-H-bonds are used as reducing agents in organic and organometallic chemistry.

[8]

Mars sand

< br>trimethylhydroxysilane

vapors to make the sand waterproof.

Silane may be used to fabricate a super-compressed, superconducting compound.

[6]

[

edit

] Safety and precautions

A number of fatal industrial accidents produced by detonation and combustion of leaked silane in air have been reported.

[9][10][11]

Dilute

silane mixtures with inert gases such as nitrogen or argon are even more likely to ignite when leaked into open air, compared to pure

silane: even a 1% mixture of silane in pure nitrogen easily ignites when exposed to air.

[12]

Unlike methane, silane is also fairly toxic: the

lethal concentration in air for rats (

LC

50

) is 0.96% over a 4-hour exposure. In addition, contact with eyes may form silicic acid with resultant

irritation.

[13]

[

edit

] See also

?

silanization

[

edit

] References

1.

^

Emelé

us, H. J. and Stewart, K. (1935).

Journal of the Chemical Society

: 1182 - 1189.

doi

:

10.1039/JR9350001182

.

2.

^

Koda, S. (1992).

Progress in Energy and Combustion

Science

18

(6): 513-528.

doi

:

10.1016/0360-1285(92)900 37-2

.

3.

^

a

b

Timms, P. L. (1999).

Journal of the Chemical Society - Dalton

Transactions

(6): 815-822. < /p>

doi

:

10.1039/a80674 3k

.

4.

^

Making Silicon from Sand

, by Theodore Gray. Originally published in

Popular Science

magazine.

5.

^

CFC Startec properties of Silane

6.

^

a

b

M. I. Eremets, I. A. Trojan, S. A. Medvedev, J. S. Tse, Y

. Yao (2008).

Science

319

(5869): 1506

–

1509.

doi

:

10.1126/science.1153282

.

PMID 18339933

.

7.

^

Graffiti protection systems

8.

^

Reductions of organic compounds using silanes

9.

^

Chen, J. R. (2002).

Process Safety Progress

21

(1): 19-25.

doi

:

10.100 2/prs.680210106

.

10.

^

Chen, J. R.; Tsai, H. Y

.; Chen, S. K.; Pan, H. R.; Hu, S. C.; Shen, C. C.; Kuan, C. M.; Lee, Y

. C.; and Wu, C. C. (2006).

explosion in a photovoltaic fabrication plant

Process Safety Progress

25

(3): 237-244.

doi

:

10.1002/prs.10136

.

11.

^

Chang, Y

. Y

.; Peng, D. J.; Wu, H. C.; Tsaur, C. C.; Shen, C. C.; Tsai, H. Y

.; and Chen, J. R. (2007).

photovoltaic fabrication plant

Process Safety Progress

26

(2): 155-158.

doi

:

10.1002/prs.10194

.

12.

^

Kondo, S.; Tokuhashi, K.; Nagai, H.; Iwasaka, M.; and Kaise, M. (1995).

Combustion and Flame

101

(1-2): 170-174.

< br>doi

:

10.1016/0010-2180(94) 00175-R

.

13.

^

See

MSDS for silane

.

Retrieved from

/ wiki/Silane

Categories

:

Silicon compounds

|

Hydrides

Making silicons

/mactest/

ring-opening polymerization

This is the page where you get to learn how easy it is to make polysiloxanes. Such polymers are usually made from monomers like

octamethylcyclotetrasiloxane. This is how we usually draw it.

You can see what it looks like in 3-D by clicking

here

.

This molecule does something fun with bases like NaOH. A hydroxide group will donate a pair of electrons to one of the silicon atoms in

the ring, which is all too happy to accept. The only problem with this is that the silicon already has its fair share of electrons, that is, eight. It

can't have ten now. So it has to get rid of a pair. The pair that gets ditched is the pair that makes up the silicon-oxygen bond. So the pair is

shifted entirely to the oxygen.

Click

here

to see a movie of this reaction.

This breaks the bond between the oxygen and the silicon. Yes, I know this bit of information comes straight out of the latest issue of the

Journal of the Blatantly Obvious

, but I bring it up for a reason. When this bond is severed, the ring is no longer a ring. It has been opened.

And furthermore, the oxygen that gained the pair of electrons now has a negative charge. It can attack a second monomer molecule,

exactly like the hydroxide attacked the first.

I think we can all see where this is heading. More monomer adds, and eventually, we get a brand new polysiloxane chain.

Because we open monomer rings to make the polymer, this is, of course, a ring-opening polymerization.