Bond length
In molecular geometry, bond length or bond distance is defined as the average distance between nuclei of two bonded atoms in a molecule. It is a transferable property of a bond between atoms of fixed types, relatively independent of the rest of the molecule.
Explanation
Bond length is related to
Bond lengths are measured in the solid phase by means of
Bond lengths of carbon with other elements
A table with experimental
Bonded element | Bond length ( pm ) |
Group |
---|---|---|
H | 106–112 | group 1
|
Be | 193 | group 2 |
Mg | 207 | group 2 |
B | 156 | group 13 |
Al |
224 | group 13 |
In | 216 | group 13 |
C | 120–154 | group 14 |
Si | 186 | group 14 |
Sn | 214 | group 14 |
Pb | 229 | group 14 |
N | 147–210 | group 15 |
P | 187 | group 15
|
As | 198 | group 15 |
Sb | 220 | group 15 |
Bi | 230 | group 15 |
O | 143–215 | group 16 |
S | 181–255 | group 16 |
Cr | 192 | group 6 |
Se | 198–271 | group 16 |
Te | 205 | group 16 |
Mo | 208 | group 6 |
W | 206 | group 6 |
F | 134 | group 17 |
Cl | 176 | group 17 |
Br | 193 | group 17 |
I | 213 | group 17 |
Bond lengths in organic compounds
The bond length between two atoms in a molecule depends not only on the atoms but also on such factors as the
Unusually long bond lengths do exist. Current record holder for the longest C-C bond with a length of 186.2 pm is 1,8-Bis(5-hydroxydibenzo[a,d]cycloheptatrien-5-yl)naphthalene,[2] one of many molecules within a category of hexaaryl ethanes, which are derivatives based on hexaphenylethane skeleton. Bond is located between carbons C1 and C2 as depicted in a picture below.
Another notable compound with an extraordinary C-C bond length is tricyclobutabenzene, in which a bond length of 160 pm is reported. Longest C-C bond within the cyclobutabenzene category is 174 pm based on X-ray crystallography.[3] In this type of compound the cyclobutane ring would force 90° angles on the carbon atoms connected to the benzene ring where they ordinarily have angles of 120°.
The existence of a very long C–C bond length of up to 290 pm is claimed in a
Shorter than average C–C bond distances are also possible:
In
The same study also estimated that stretching or squeezing the C–C bond in an ethane molecule by 5 pm required 2.8 or 3.5 kJ/mol, respectively. Stretching or squeezing the same bond by 15 pm required an estimated 21.9 or 37.7 kJ/mol.
C–H | Length ( pm ) |
C–C | Length (pm) | Multiple-bonds | Length (pm) |
---|---|---|---|---|---|
sp3–H | 110 | sp3–sp3 | 154 | Benzene | 140 |
sp2–H | 109 | sp3–sp2 | 150 | Alkene | 134 |
sp–H | 108 | sp2–sp2 | 147 | Alkyne | 120 |
sp3–sp | 146 | Allene |
130 | ||
sp2–sp | 143 | ||||
sp–sp | 137 |
References
- ISBN 0-8493-0465-2.
- hdl:2115/73547.)
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: CS1 maint: multiple names: authors list (link - doi:10.1002/(SICI)1099-0690(200004)2000:8<1377::AID-EJOC1377>3.0.CO;2-I. Archived from the originalon 2012-06-29.
- doi:10.1002/1521-3773(20010702)40:13<2540::AID-ANIE2540>3.0.CO;2-O. Archived from the originalon 2012-06-29.
- PMID 14519002.
- PMID 16492025.
- PMID 16259033.
- PMID 20718457.
- ISBN 978-3-86025-249-9.