Jump to ContentJump to Main Navigation
The Chemical Bond in Inorganic ChemistryThe Bond Valence Model$

I. David Brown

Print publication date: 2006

Print ISBN-13: 9780199298815

Published to Oxford Scholarship Online: January 2010

DOI: 10.1093/acprof:oso/9780199298815.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (www.oxfordscholarship.com). (c) Copyright Oxford University Press, 2017. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a monograph in OSO for personal use (for details see http://www.oxfordscholarship.com/page/privacy-policy). Subscriber: null; date: 25 February 2017

(p.244) Appendix 4

(p.244) Appendix 4

Cation and anion bonding strengths

Source:
The Chemical Bond in Inorganic Chemistry
Publisher:
Oxford University Press

Table A4.1 Bonding strengths for cations

Element

Atomic valence

Bonding strength (vu)

Ideal coordination number

H

1 +

0.82, 0.18

 

Li

1 +

0.205

4.9

Na

1 +

0.156

6.4

K

1 +

0.126

7.9

Rb

1 +

0.124

8.0

Cs

1 +

0.109

9.2

Be

2 +

0.501

3.99

Mg

2 +

0.334

5.98

Ca

2 +

0.274

7.31

Sr

2 +

0.233

8.57

Ba

2 +

0.195

10.24

Sc

3 +

0.49

6.2

Y

3 +

0.43

7.0

La

3 +

0.35

8.5

Ti

4 +

0.67

6.0

Zr

4 +

0.60

6.7

V

5 +

1.08 (average)

4.6

V

4 +

0.71

5.6

V

3 +

0.50

6.0

Nb

5 +

0.82

6.1

Ta

5 +

0.82

6.1

Cr

6 +

1.50

4.0

Cr

3 +

0.50

6.0

Mo

6 +

1.23

4.9

W

6 +

1.07

5.6

Mn

4 +

0.67

6.0

Mn

3 +

0.52

5.8

Mn

2 +

0.34

5.9

Re

7 +

1.51

4.6

Re

5 +

0.83

6.0

Fe

3 +

0.53

5.7

Fe

2 +

0.34

5.9

Ru

5 +

0.83

6.0

Co

3 +

0.51

5.9

Co

2 +

0.35

5.7

Rh

3 +

0.50

6.0

Ni

2 +

0.34

5.9

Pd

2 +

0.46

4.4

Pt

4 +

0.67

6.0

Cu

2 +

0.45, 0.20

5.1

Cu

1 +

0.45

2.2

Ag

1 +

0.12–0.50

5.1

Zn

2 +

0.33–0.50

5.0

Cd

2 +

0.25–0.40

6.1

Hg

2 +

0.25–0.50

5.5

B

3 +

0.87

3.46

Al

3 +

0.57

5.27

Ga

3 +

0.65

4.62

In

3 +

0.50

5.98

Tl

3 +

0.49

6.1

Tl

1 +

0.11–0.33

6.9

C

4 +

1.35

2.96

Si

4 +

1.00

4.02

Ge

4 +

0.89

4.51

Sn

4 +

0.68

5.86

Sn

2 +

0.4–0.7

4.4

Pb

4 +

0.70

5.73

Pb

2 +

0.2–0.5

6.9

N

5 +

1.67

3.00

P

5 +

1.25

4.01

As

5 +

1.13

4.41

As

3 +

0.98

3.07

Sb

5 +

0.83

6.05

Sb

3 +

0.43–0.75

4.8

Bi

3 +

0.37–0.75

6.2

S

6 +

1.5

4.0

S

4 +

1.0–1.3

3.4

Se

6 +

1.5

4.0

Se

4 +

1.2

3.3

Te

6 +

1.0

6.0

Te

4 +

0.8–1.3

4.1

Cl

7 +

1.75

4.0

I

7 +

1.2

5.6

I

5 +

1.3

3.8

NH4

1 +

0.12–0.25

 

N(CH3)4

1 +

0.083

 

The bonding strengths and ideal coordination numbers (average coordination numbers observed for O ligands) are mostly taken from Brown (1988a). For soft cations a range of bonding strengths is given. The cations are ordered by group, then by period, and then by oxidation state. Complex cations are given at the end. A range of bonding strengths is given for soft cations.

(p.245)

(p.246)

Table A4.2 Bonding strengths for mixed anions and cations

Complex

Cation bonding strength (vu)

Anion bonding strength (vu)

H2O (liquid)

0.17

0.17

H2O (solid)

0.20

0.20

HF

0.17

0.06

NH3

0.17

0.50

(CH3)2SO (dmso)

0.07

0.25

Table A4.3 Bonding strengths for anions

Anion

Formal charge

Bonding strength

I

1 −

0.083⋆

ClO4

1 −

0.083

Br

1 −

0.100⋆

NO3

1 −

0.111

Cl

1 −

0.142⋆

H2PO4

1 −

0.167

HCO3

1 −

0.167

SO4

2 −

0.167

HPO4

2 −

0.22

CO3

2 −

0.22

F

1 −

0.25

PO4

3 −

0.25

BO3

3 −

0.33

SiO4

4 −

0.33

OH

1 −

0.39

O

2 −

0.50

The anions are arranged in order of increasing bonding strength. These values are calculated by assuming that O is four coordinate. The method of calculating bonding strengths of protonated anions is described in Section 5.4. Anions marked with an asterisk (⋆) are soft and can adopt a range of bonding strengths. Only the lower limit is shown.