Nitrogen has five valence electrons and in simple amines it is trivalent with two remaining electrons forming a lone pair. Through it, nitrogen can form an additional bond to hydrogen making it tetravalent and with a positive charge in ammonium salts. Many nitrogen compounds can thus be potentially basic but its degree depends on the configuration: the nitrogen atom in amides is not basic due to delocalization of the lone pair into a double bond and in pyrrole the lone pair is part of an aromatic sextet.
In common with carbon-carbon bonds, these bonds can be stable double bonds for instance imines and triple bonds such as nitriles. Bond lengths range from 147.9 pm for simple amines to 147.5 pm for C-N= compounds such as nitromethane to 135.2 pm for partial double bonds in pyridine to 115.8 pm for triple bonds as in nitriles . The bond strength in a CN bond is higher (184 kcal/mol) than that of the CC bond (145 kcal/mol)
A CN bond is strongly polarized towards nitrogen (electronegativity for C and N is 2.55 and 3.04, respectively) and subsequently molecular dipole moments can be high: cyanamide 4.27 D, diazomethane 1.5 D, methyl azide 2.17, pyridine 2.19. For this reason many compounds containing CN bonds are water-soluble.
|Chemical class||Bond order||Formula||Structural Formula||Example||Avg. C–N bond length (Å)|
| 1.469 (neutral amine)|
1.499 (ammonium salt)
| 1.355 (sp2 N) |
1.395 (sp3 N)
1.465 (ammonium salt)
| 1.325 (primary)|
| 1.279 (C=N bond)|
1.465 (C–N bond)
WIPO ASSIGNS PATENT TO MASSACHUSETTS INSTITUTE OF TECHNOLOGY FOR "METAL-CATALYZED CARBON-FLUORINE BOND FORMATION" (AMERICAN, SINGAPOREAN INVENTORS)
Jan 21, 2011; GENEVA, Jan. 21 -- Publication No. WO/2011/008725 was published on Jan. 20. Title of the invention: "METAL-CATALYZED...
WIPO ASSIGNS PATENT TO MASSACHUSETTS INSTITUTE OF TECHNOLOGY, NATIONAL UNIVERSITY OF SINGAPORE FOR "METAL-CATALYZED CARBON-FLUORINE BOND FORMATION" (AMERICAN, SINGAPOREAN INVENTORS)
Jan 23, 2011; GENEVA, Jan. 23 -- Publication No. WO/2011/008618 was published on Jan. 20. Title of the invention: "METAL-CATALYZED...