主族 (Main groups)

• The members of a group have analogous valence-shell electron configurations.

• The element at the head of a group often has a character that is quite distinct from the other members of the group.

• There are diagonal relationships between elements, especially between Periods 2 and 3.

• There is a trend toward metallic character on going to the left along a period and on going down a group.

元素的性质• He-Rn ， 天然存在形式 , 单原子气体； Ar, the 3rd mo

st abundant gas in the atmosphere (after N2, O2); He, th

e 2nd abundant element in the universe after H, rare on Earth. A component of natural gases (notably Texas)

• He, Buoyancy in airships; dilute O2; coolant; He-Ne lase

rs. Cryogenics, superfluidity (<2K); Only substance known to have more than one liquid phase.

• Ne, emits a red glow when an electric currents through it.

• Ar, provide an inert atmosphere. (light bulbs)

• Kr, intense white light, airport runway lighting.

• Xe, in halogen lamps. Anesthetic ( 麻醉剂 )

Ne

Ne+(Ar)

Ne: advertising signs; Ar: in some light bulbs (导热 )

Kr: airport runway lighting; Xe: in halogen lamps for (intense white light) automobile headlights

电离能

Xe + PtF6 → XePtF6 (1962)

KrF2; Ke-N (1988, stable below –50ºC)

XeF2, XeF4, XeF6

Powerful fluorinating agents

Pt(s) + XeF4(s) → Xe(g) + PtF4(s)

Xe-F

Crystals of XeF4

Only xenon is known to form en extensive series of compounds with fluorine and oxygen.

Xenon fluorides are powerful fluorinating agents, and xenon oxides are powerful oxidizing agents.

卤素 Halogen (“ 成盐” )

I2, Br2, Cl2

F2, Cl2, Br2, I2, 最大吸收波长 长， 减小

分子轨道理论

电负性

增

减

电负性数据

原子和离子半径

元素的性质 (F, Cl)• F ， 天然存在形式 , CaF2, Na3AlF6, Ca5F(PO)3

• F2, 最强的氧化剂， Eo = +2.87 V, 电解 (KF+HF)

5×106 Kg / y in US, UF6 (volatile solid), processing 核燃料；SF6, electrically insulating gas; Fluorinated hydrocarbons, Teflon, Freon( 氟利昂 ), they are inert.

大多数氟化物溶解性 低 ( 除 AgF) ，尽管其丰度比 Cl 大。• Cl2 ， 电解 NaCl (pale yellow-green gas) • It reacts directly with nearly all the elements ( 除 C,N,O, no

ble gases ). 强的氧化剂 , 氧化金属到高氧化态，如： 2Fe(s) + 3Cl2 → 2FeCl3(s) → 塑料，溶剂，杀虫剂 ; 漂白纸，纺织品；水消毒

2004年 7月 8日，美国环保署 (EPA)宣布，杜邦公司由于在过去的 20多年来从未通报特富龙制造过程中的一种成分——全氟辛酸铵可能对人体有害，已经违反了毒物管制法，决定对其处以 3亿美元的巨额罚款。

HF + KF = KHF2, 2KHF2 = 2KF + H2 + F2

阳极

氧化 F- 到 F

2

阴极

还原 H+ 到H2

阳极

氧化 Cl- 到Cl2

阴极

还原 H2O 到 H

2

2NaCl(aq)+2H2O(l)=2NaOH(aq)+Cl2(g)+H2(g)电解池

2Fe(s) + 3Cl2 → 2FeCl3(s)

2Br-(aq) + Cl2(g)

→ Br2(l) + 2Cl-(aq)

元素的性质 (Br, I)

• Br2, 腐蚀性红棕色冒烟液体• 有机合成中，加溴和去溴• I2 ， 海藻 2000 Kg → 1 kg I2

Cl2(g) + 2I-(aq) → I2(aq) + 2Cl-(aq)

易升华，固态 I2 分子仍为孤立分子，不象 C,Si,P,S 那样形成原子链或网。(I2+KI+ 乙醇 ), 碘酒，消毒杀菌碘缺乏症 (swelling of the thyroid gland in the neck)

I2 的溶液： CCl4, H2O, KI, 淀粉 +KI

The picture above shows the result of touching nitrogen triiodide (NI3)! Nitrogen triiodide is percussion (碰击 ) sensitive.

互卤化物

Cl2(g) + 3F2(g) → 2ClF3(g)

Cl2(g) + 5F2(g) → 2ClF5(g)

物性：介于两种单质之间；

化性：取决于 X-X’ 键能

(X heavier, decreasing)

价层电子对互斥理论

H2(g) + X2(g) → 2HX(g)

CaF2(s) + 2H2SO4 (aq, conc) → Ca(HSO4)2(aq)+ 2HF(g)

KI(s) + H3PO4 (aq) → KH

2PO4(aq)+ HI(g)氢键

(HF + NH4F) frosts the glass surface

SiO2(s) + 4HF(aq) → SiF4(g) + 2H2O(l) Go = -12.0kJ/mol

HF 具有强腐蚀性！

生成焓 晶格能 晶格能生成焓

离子型氯化物的生成焓和晶格能

电子亲核能解离能

升华热 + 电离能

含氧酸

亚

次

高

非羟基氧数目，酸性

(正 )

Cl2(g) + H2O(aq) → HClO(aq) + HCl(aq)

unstable

Cl2(g) + 2OH-(aq) → ClO-(aq) + Cl-(aq) + H2O(l)

ClO- — Cl2 — Cl-

0.40 V 1.36 V

Cl2(g) + CaO(s) ( 生石灰 ) → Ca(ClO)2 净化游泳池水

(“84” 消毒液主要成分： NaClO)

HX(I)O .. ..:Cl-O-H

.. ..

注意： 注意： 一般来说一般来说 , , EE33 E E

22 – E – E11

GG 具有加合性，而 具有加合性，而 EE 不具加合性，为强度量。不具加合性，为强度量。元素电势图：元素电势图：

将同一种元素的不同物种，按氧化态从高到低的顺序排列，将同一种元素的不同物种，按氧化态从高到低的顺序排列，两物种间用横线相连，将其对应电对的两物种间用横线相连，将其对应电对的 EE 标注在横线上面。标注在横线上面。

)V(52.05

44.0154.04

n

EnEnE

2

33112

EEBB(V)(V): : BrOBrO33

-- ——— BrO BrO-- ——— Br Br22 0.540.54 0.440.44EE11

EE33

0.520.52EE22

(+5) (+1) (0)(+5) (+1) (0)

)V(54.04

44.0152.05

n

EnEnE

1

33221

例：例：

)V(52.01

16.0134.02

n

EnEnE

2

11332

EEAA(V)(V): : CuCu2+2+ ——— Cu Cu++ ——— Cu Cu 0.160.16 0.520.52

EE11 EE22

0.340.34EE33

)V(16.01

52.0134.02

n

EnEnE

1

22331

)V(34.02

52.0116.01

n

EnEnE

3

22113

若 E右 > E

左 时， 发生歧化反应

2 Cu+ ＝ Cu2+ + Cu

3Cl2(g) + 6OH-(aq) △→ ClO3-(aq) + 5Cl-(aq) + 3H2O(l)

分解

4KClO3(s) △ → 3KClO4(s) + KCl(s)

2KClO3(s) (MnO△ 2) → 2KCl(s) + 3O2(g)

氧化剂 ( 焰火，火柴 )

2NaClO3(aq) + SO2(g) + H2SO4(aq)

→ 2NaHSO4(aq) + 2ClO2(g)

(paramagnetic yellow gas, 漂白纸浆 )

HX(V)O3 ， HX(VII)O4

ClO3-(aq) +H2O(l) → ClO4

-(aq) + 2H+(aq) + 2e-

HClO4, 无色液体，最强酸。 Powerful 氧化剂，爆炸！

The perhalic acids and their anions are strong oxidizing agents. They do, however, have considerable kinetic stability.

Frost (or Latimer) diagram display the same information but in a different way. When interpreting electrode potential data, either in numerical or graphical form, it is important to remember that a single potential in isolation has no meaning!

The interhalogens ( 互卤化物 ) have properties intermediate between those of the constituent halogens.

Nonmetal form covalent halides; metal form ionic halides. ( 共价与离子型卤化物 )

The oxoacids of chlorine are all oxidizing agent. Acidity and oxidizing strength of oxoacids both increase as the oxidation number of the halogen increase.

( 含氧酸的酸性与氧化性 )

氧 ( 硫 ) 族 Chalcogen (“ 成矿” )

23% of the mass of the atmosphere

Liquid oxygen is pale blue (<-183ºC)

The gas is colorless.

Paramagnetic

2 ×1010 kg LO2/y (US)

Ca. 80kg/person

Steel industry

光解水： 2H2O(l) →2 H2(g) + O2(g)

光合作用： 6CO2(g) + 6H2O(l) → C6H12O6(s) + 6O2(g)

A blue gas, dark blue liquid;

Pungent smell;

Cover the Earth (3mm)

处理含 CN- 电镀液 : 5O3 + 2CN- + H2O = 2HCO3- + N2 +5O2

南极臭氧层空洞

“臭氧层破坏的危害”

臭氧层的破坏　　卫星观测资料表明，自 20世纪 70年代末以来，全球臭氧总量明显减少， 1979－ 1990年，全球臭氧总量大致下降了 3% 。南极附近臭氧量减少尤为严重，出现了“南极臭氧洞”。　　　　平流层臭氧量的减少，除了受太阳活动等自然因子的影响外，人类使用消耗臭氧物质也是重要原因。人们使用冰箱、空调等释放出的氟氯烃化合物，上升到平流层后，通过光化学反应大量消耗臭氧。据研究，大气中的臭氧总量减少 1% ，到达地面的太阳紫外线辐射就会增加 2% 。到达地面的太阳紫外线辐射增加，一方面直接危害人体健康，另一方面还对生态环境和农林牧渔业造成破坏。为此，臭氧层保护被认为是当今全球最重要的环保项目之一。　　为了保护臭氧层，国际社会多次召开会议，要求各国减少并逐步禁止氟氯烃等消耗臭层物质。

PbS HgS FeS2 ZnS

冶金 (Cu)副产物；富硫石油

2H2S(g)+3O2(g)=2SO2(g)+H2O(l)

2H2S(g)+SO2(g)=3S(s)+H2O(l)

S8(s) →113°C S8(l)

→ △ Chain (red-brown)

→ △ S3, S2(like O2)

硫的用途：

Sulfuric acid, vulcanize rubber

（硫酸，硫化橡胶）

Block-like rhombic form S Needlelike monoclinic S

Se Te

Like silver-white metals, but poor electrical conductors

电负性

增

减

电负性数据

原子半径和离子半径

Metallic character increases down Group 16 as electronegativity decreases.

从上到下，电负性减小，金属性增强。

Oxygen and sulfur occur naturally in the elemental state. Sulfur forms long chains and rings with itself, but oxygen does not.

Compounds with hydrogen

• H2O 的纯化：离子交换除钙，镁离子；• H2O是氧化剂：

2H2O(l)+2e-→2OH-(aq)+H2(g) E = -0.42V at pH=7

2Na(s)+2H2O(l) →2NaOH(aq)+H2(g)

BUT, 除非有强还原剂， H2O只有在高温下才起氧化剂作用， 如 CH4(g)+H2O(g) → CO(g)+3H△ 2(g) ( 合成气 )

• H2O是还原剂 (mild) ：2H2O(l) →4H+(aq)+O2(g)+4e- E=-0.81V at pH=7

• Lewis base → [Fe(H2O)6]3+

Structural snapshot.

Liquid water, probed on the sub-femtosecond time scale by x-ray absorption spectroscopy, consists of structures with two strong hydrogen bonds of each molecule to its neighbors, resulting in water chains and rings.

New Insights into the Structure of Water with Ultrafast Probes

Yan Zubavicus and Michael Grunze

SCIENCE,304,974-5. 14 MAY 2004

Very pale blue liquid; d: 1.44 g/ml at 25°C; mp, bp: -0.4, 152 °C

Very weak acid, pKa1 = 11.75

Good oxidizing agent in both acidic and basic solution; (Fe2+, Mn2+)

Also act as a reducing agent (MnO4-, Cl2)

H2O2 + CH3COOH - CH3C(O)-OOH (过氧乙酸， 0.5% 杀菌消毒 )

工业应用 : 30%

Hair bleach ( 漂白 ): 6%

家用防腐杀菌： 3%

Water can act as a Bronsted acid, a Bronsted base, a Lewis base, an oxidizing agent, and a weak reducing agent.

Hydrogen peroxide is a strong oxidizing agent.

Hydrogen sulfide is a weak acid.

Sulfur can catenate ( 连接 ) to form polysulfanes( 多硫烷 ).

Sulfur oxides and oxoacids硫的氧化物与含氧酸

S + O2 → SO2; 植被分解和火山爆发；燃油和煤 ( 电厂 )

H2S(g) + 3O2(g) → 2SO2(g) + 2H2O(g)

酸性氧化物

SO2(g) + H2O(l) → H2SO3(aq) (an equilibrium mixture,见后图 )

还原性和氧化性

SO2(g) + Br2(aq) → Br-(aq) + SO4-(aq)

2SO2(g) + O2(g) △→ 2SO3(g), slow reaction, catalyzed V2O5

SO3(g) + H2O(l) → H2SO4(aq) 酸雨（ SOx, NOx, H2O）

H2SO4, 无色腐蚀油状液体；强酸，脱水剂，氧化剂。

SO3(g) + H2SO4(l) → H2S2O7(l) (Oleum, 发烟硫酸 )

化肥（ 2/3），石化产品，染料，清洁剂。

SO2 ， SO3, H2S(IV)O3, H2S(VI)O4

火山喷发的气体中含有大量的二氧化硫

硫代硫酸根

硫酸根

亚硫酸

SO2(g) + Br2(aq)

→ Br-(aq) + SO4-(aq)

SO2(g) + MnO4- (aq) ?

SO2(g) + CrO42- (aq) ?

H2SO4(浓 ) + NaBr(aq)

→ Br2

C12H22O11(s) → 12C(s) + 11H2O

蔗糖脱水

Sulfur dioxide (SO2) is the acid anhydride ( 酸酐 ) of sulfurous acid (亚硫酸 ), and sulfur trioxide (SO3) is the anhydride of sulfuric acid ( 硫酸 ).

Sulfuric acid ( 硫酸 ) is a strong acid, a dehydrating agent, and an oxidizing agent.

金属硫化物纳米线气相沉积及生长机制

Metal chloride + S powder

metal sulfide NWs

Au, 650 C2 2 2CdCl 3S CdS S Cl

Chem. Comm. 2003, 19, 2498 Adv. Funct. Mater. 2004, 14 (2): 157-162

金属硫化物纳米线

2μm

Bi2S3

过渡金属掺杂的 ZnS纳米带及其荧光调控

CdS 一维纳米阵列的催化生长

ZnSe微米空心球的设计与合成

Angew. Chem. Int. Ed. 2003, 42 , 3027.

ZnSe微米空心球的光学特性

沉淀 /溶解平衡竞争合成系列半导体空心微球

CdSe空心微球

Synthesis and Size-Dependent Magnetic Properties of Monodisperse EuS Nanocrystals

Fei Zhao, Hao-Ling Sun, Gang Su, Song Gao

Small 2005, online.