STRUCTURE OF SOLIDS Types of solids based on structure Types of solids based on bonding.
Bonding in Solids -...
Transcript of Bonding in Solids -...
![Page 1: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/1.jpg)
1
Bonding in Solids
• What is the chemical bonding?• Bond types:
– Ionic (NaCl vs. TiC ?)– Covalent– Van der Waals– Metallic
![Page 2: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/2.jpg)
2
Ions and Ionic Radii
LiCl
![Page 3: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/3.jpg)
3
Ions(a) Ions are essentially spherical.(b) Ions may be regarded as composed of two
parts: a central core in which most of the electron density is concentrated and an outer sphere of influence which contains very little electron density.
(c) Assignment of radii to ions is difficult; even for ions which are supposedly in contact, it is not obvious where one ion ends and another begins.
![Page 4: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/4.jpg)
4
Where is the border bet. M+ and N- ?
1. Ions are charged, but they cannot be regard as hard sphere.
2.The e- density does not decrease abruptly to zero.
![Page 5: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/5.jpg)
5
Ions in Crystal
1.Similar to Pauling & Goldschmidt’s table.2. Based on r(O2-) and r(F-).3. Obtained from X-ray electron density map.
![Page 6: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/6.jpg)
6
Ionic Radiia) s- and p-block elements: radii increase with
atomic number for vertical group b) For isoelectronic cations, radii decrease with
increassing charge.c) For element which can have > +1 oxidation
state, the radius decreases with increasing oxidation state, e.g. V2+, V3+, V4+, V5+.
d) For an element which can have various coordination numbers, the cationic radius increases with increasing coordination number.
![Page 7: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/7.jpg)
7
Ionic Radii cont.e) Lanthanide contraction (due to ineffective
shielding of the nuclear charge by the d and, especially, f electrons), e.g. La3+ (1.20 A) --Eu3+
(1.09 A)--Lu3+ (0.99 A). f) The radius of a particular transition metal ion is
smaller than that of the corresponding main group ion for the reasons given in (e), e.g. octahedral radii, Rb+(1.63 A) and Ag+ (1.29 A) or Ca2+ (1.14 A) and Zn2+ (0.89 A).
g) Diagonal relationship: Li+ (0.88 A) and Mg+2
(0.86 A).
![Page 8: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/8.jpg)
8
2.3 Ionic Structurea) Ions are charged, elastic and polarizable
spheres.b) Ionic structures are held together by
electrostatic forces and are arranged so that cations are surrounded by anions, and vice versa.
c) To maximize the net electrostatic attraction between ions (i.e. the lattice energy), coordination numbers are as high as possible, provided that the central ion 'maintains contact' with its neighboring ions of opposite charge.
![Page 9: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/9.jpg)
9
Ionic Structure cont.
(d) Next nearest neighbor interactions are of the anion-anion and cation - cation type and are repulsive. Like ions arrange themselves to be as far apart as possible and this leads to structures of high symmetry with a maximized volume.
(e) The valence of an ion is equal to the sum of the electrostatic bond strengths between it and adjacent ions of opposite charge. (Pauling’selectrostatic valence rule.)
![Page 10: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/10.jpg)
10
Rutile
![Page 11: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/11.jpg)
11
Electrostatic bond strength• For a cation Mm+ surrounded by n anions,
Xx-
ebs = m/n∑(m/n) = x
• MgAl2O4:Mg2+ (Td site) ebs = 2/4 = ½Al3+ (Oh site) ebs = 3/6 = ½
Oxygen charge ∑ebs(3Al3+ + 1Mg2+) = 2 (Each O atom is surrounded by three Al3+
and one Mg2+ cations, the observed charge is equal to oxygen’s charge)
![Page 12: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/12.jpg)
12
• SiO4 cannot share a common corner in silicate structures:
• Si4+: ebs = 4/4 = 1
• Two Td corner: ebs = 2 (O atom connect to two Si atoms)
• Three Td corner: ebs = 3 (unreasonable)
![Page 13: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/13.jpg)
13
![Page 14: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/14.jpg)
14
The radius ratio rule
(2rx)2 + (2rx)2
=[2(rM+rx)]2
2rx√2 = 2 (rM+rx)
rM/rx = 0.414
![Page 15: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/15.jpg)
15
![Page 16: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/16.jpg)
16
• A cation must be in contact with its anionic neighbors.
• Neighboring anions may or may not be in contact.
![Page 17: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/17.jpg)
17
![Page 18: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/18.jpg)
18
Borderline Radius & Distorted Structures
V2O5 Orthorhombic, Pnma
![Page 19: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/19.jpg)
19
ZrO2
2.25
2.16
2.16
2.19
2.56
2.56
2.27
2.27
2.10
Orthorhombic, Pnam
![Page 20: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/20.jpg)
20
PbTiO3
Tetragonal, P4mm
![Page 21: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/21.jpg)
21
Lattice Energy
NaCl(s) Na+(g) + Cl-(g)ΔH = U
a) Electrostatic forces attractionV = - (Z+Z-e2)/r
b) Short-range repulsive forcesV = B/rn
reZZFdrV
r 2−+
∞−== ∫
![Page 22: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/22.jpg)
22
Madelung constant
N : M constant
![Page 23: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/23.jpg)
23
2.6 Lattice Energy
![Page 24: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/24.jpg)
24
nrBN
rNAeZZU +−= −+
2
Therefore,1
2
+−+ −= nr
nBNr
NAeZZdr
dU
when 0=dr
dU
then
nNAreZZB
n 12 −−+=
and therefore
)11(2
nrNAeZZU
e
−−= −+
Lattice Energy I
![Page 25: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/25.jpg)
25
Van der Waals or London forces, zero-point energy, correction for heat capacity
Lattice Energy II
![Page 26: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/26.jpg)
26
Kapustinskii’s eq.1-molkJ 345.015.1200
⎟⎟⎠
⎞⎜⎜⎝
⎛+
−+
= −+
acac rrrrZVZU
V: # of ions per formula unit
![Page 27: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/27.jpg)
27
![Page 28: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/28.jpg)
28
Born-Haber Cycle
ΔHf = S + (1/2)D + IP + EA + U (could be estimated) = 109 + 121 + 493.7 + (-356) + (-764.4)= -410.9 kJ mol-1
![Page 29: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/29.jpg)
29
The Synthesis of XePtF6
• XePtF6 was first synthesized by Barlett at 1962.
• The idea for this compound is from the formation of O2PtF6 (O2)+(PtF6)-
• The 1st IE of O2 (1169 kj/mol) and Xe(1176 kj/mol) are similar!
![Page 30: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/30.jpg)
30
![Page 31: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/31.jpg)
31
Stabilities of Real and Hypothetical ionic compounds
S 0.5D IP EA U ΔHf (calc)
NaCl -764.4 kJ mol-1
KCl -701.4
ArCl 0 121 1524 -356 -754 544
![Page 32: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/32.jpg)
32
Partial Covalent Bonding
SrO HgOsp hybridization?
![Page 33: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/33.jpg)
33
AlF3, AlCl3, AlBr3, AlI3 ionic – covalent
AlF3 AlCl3
AlBr3 (Al2Br3 unit) AlI3 (Al2I3 unit)
![Page 34: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/34.jpg)
34
Sanderson’s Model
• To calculate partial charge of atom• To evaluate ionic and covalent bonding for
total energy of ionic compounds– Effective nuclear charge– Atomic radii (r = rc - Bδ; δ = ΔS/Sc)– Electronegativity and charged atoms
![Page 35: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/35.jpg)
35
Effective Nuclear Charge
• The positive charge that would be felt by a foreign electron on arriving at the periphery of the atom.
• The valence electrons are not very effective in shielding the outside world from the positive charge on the nucleus. Therefore, any incoming e- feels a positive, attractive charge.
![Page 36: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/36.jpg)
36
Screening constants
• The value of screening constants in different elements could be obtained theoretically.
• The valence electron experience an increasingly strong attraction to the nucleus on going from sodium (Na) to chlorine (Cl).
![Page 37: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/37.jpg)
37
Atomic Radius
• Atomic radii vary considerably for a particular atom depending on bond type and CN.
• With increasing amount of partial positive charge, the radii become smaller
• Sanderson’s model:r = rc - Bδ
rc: non-polar covalent radius; δ: partial charge (estimated)
![Page 38: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/38.jpg)
38
Electronegativity and Partially Charged Atoms
• The magnitude of the partial charge depends on the initial difference in electronegativity between the two atoms.
• Sanderson’s model for electronegativity:S = D/Da
D: electron density of the atom (atomic number/atomic volume)
Da: expected electron density
![Page 39: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/39.jpg)
39
![Page 40: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/40.jpg)
40
Electronegativity Equalization
• When two or more atom initially different in electronegativity combine chemically, they adjust to have the same intermediate electronegativity within the compound.
• NaF: geometric mean of their χ
006.2== FNab SSS
![Page 41: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/41.jpg)
41
Partial Charge
• The ratio of the change in electronegativityundergone by an atom on bond formation to the change it would have undergone on becoming completely ionic with charge + or -1.
• NaF: Assume 75% ionic∆Sc = 2.08/S (changes in χ)Partial charge δ = ∆S/ ∆Sc∆S = S - Sb
![Page 42: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/42.jpg)
42
Example: BaI2• SBa = 0.78; SI = 3.84• Sb = 3/SBaSI
2 = 2.26
• For Ba, ∆S = 2.26 – 0.78 = 1.48• For iodine ∆S = 3.84 – 2.26 = 1.58• ∆Sc: 1.93 (Ba), 4.08(I) (from tab. 2.10)• δBa = 1.48/1.93 = 0.78• δI = 1.58/4.08 = -0.39• The result suggest BaI2 is ~ 39% ionic
![Page 43: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/43.jpg)
43
• The radii of the partially charged atom:
Ba: rBa = rc - Bδ = 1.98 – 0.348x0.78 = 1.71 Å
rI = 1.87 Åd(Ba-I) = 3.58 Å (exp = 3.59 Å)
![Page 44: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/44.jpg)
44
• It is unrealistic and misleading to assign a radius to the chloride ion which is constant for all solid chlorides.
![Page 45: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/45.jpg)
45
• Calculations show that the actual charge carried by an oxygen never exceed -1 and is usually much less than -1.
![Page 46: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/46.jpg)
46
Mooser-Pearson plots and Ionicities
![Page 47: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/47.jpg)
47
bcc
fcc
![Page 48: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/48.jpg)
48
Bond Valence and Bond Length
• Most molecular materials may be described satisfactorily using valence bond theory.
• For non-molecular inorganic materials, the VBT is not always fit.
• Pauling, Brown, Shannon, Donnay et. al. : Bond order (bond valence) in a structure.
![Page 49: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/49.jpg)
49
• Bond valences are defined empirically.• Valence rule:
Vi: valence of atom Ibvij: bond valence between atom i and j
∑=j
iji bvV
![Page 50: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/50.jpg)
50
![Page 51: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/51.jpg)
51
Applications
• To check the valence state of cation atom.• To locate the position of H+
• To distinguish between Al3+ and Si4+
• Transition metals in oxide compounds
![Page 52: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/52.jpg)
52
Non-bonding electron effects• d-electrons in transition metal compounds
![Page 53: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/53.jpg)
53
![Page 54: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/54.jpg)
54
![Page 55: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/55.jpg)
55
Ca2+ Mn2+ Zn2+
![Page 56: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/56.jpg)
56
Crystal Field Stabilization Energy
![Page 57: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/57.jpg)
57
Jahn-Teller distortions
d9 (Cu2+), d7 (LS) and d4 (HS, Cr2+)
![Page 58: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/58.jpg)
58
• Cu2+(d9), Cr2+ (d4)-MO oxides:Ti, V, Mn, Fe, Co, Ni: NaCl-typeCuO: distorted CuO6 octahedralCrO: NA
• MF2:-Ti, V, Mn, Fe, Cu, Ni, Zn: rutile-Cr, Cu: distorted rutile
![Page 59: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/59.jpg)
59
Square plannar coordination
• d8 ions: Ni2+, Pd2+, Pt2+
• Square planar coordination is more common with 4d and d transition elements.
![Page 60: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/60.jpg)
60
Tetrahedral Coordination
The magnitude of the splitting is generally less in a tetrahedral field.
![Page 61: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/61.jpg)
61
![Page 62: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/62.jpg)
62
Inert Pair Effect
• Heavy, post-transition metals: Tl, Sn, Pb, Sb, Bi
• These metals usually exhibit a valence state that is two less than the group valence. Inert pair effect
• Example: Pb+2 environment in PbTiO3
![Page 63: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/63.jpg)
63
PbTiO3
Tetragonal, P4mm
Pb
![Page 64: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/64.jpg)
64
Non Linear Optic Materials
Pb6Ti2Nb8O30Cm2m
Chem. Mater. 2004, 16, 3616-3622
![Page 65: Bonding in Solids - ocw.nctu.edu.twocw.nctu.edu.tw/course/sschemistry/sschemistry_lecturenotes/ssch-2...1 Bonding in Solids • What is the chemical bonding? • Bond types: – Ionic](https://reader031.fdocuments.net/reader031/viewer/2022021511/5abda6807f8b9a5d718beec5/html5/thumbnails/65.jpg)
65