Non-conventional hydrogen bonds

Therefore, it may be concluded that non-conventional hydrogen bonds can play an important role in determining the supramolecular structure of gold complexes. 

The conventional hydrogen bond X-H- Y is formed by the proton donor X-H with a proton acceptor Y, which is an atom with a lone pair (X and Y are all highly electronegative atoms such as F, O, N, and Cl). Some non-conventional hydrogen bonds that do not conform to this condition are discussed below ... 

Figure 3. Examples of inter- and intramolecular non-conventional hydrogen bonds.

Meng, Y., Zhou, Z., Duan, C., Wang, B., and Zhong, Q., Non-conventional hydrogen bonding interaction of BH3NH3 complexes a comparative theoretical study, J. Mol. Struct. Theochem, 713, 135-144 (2005). 

In addition to this broad class of conventional hydrogen bonds, several non-conventional variants also exist in nature [2-7]. For example, hydrogen bonds occur in systems with non-conventional hydrogen acceptors, such as isonitriles [8, 9], carbanions [10, 11], carbenes and silynes [12], n-systems [8, 9, 13]. Non-conventional hydrogen bonds also include those known as hydridic, also termed inverse hydrogen bonds since they are characterised by an inverted polarity [9], that is and a newly characterised... 

Alkorta I, Rozas I, Elguero J. Non-conventional hydrogen bonds. Chem Soc Rev 1998 27 163-170. 

Reviews. - In a recent review Alkorta et a/.191 discuss non-conventional hydrogen bonds (HB), which are much more exotic than the once unconventional C-H - O hydrogen bond. Their survey includes HBs such as C-H - C, where isocyanides, CO or carbanions and zwitterions act as HB acceptors. 

Desiraju, G.R., Steiner, T. Other Weak and Non-Conventional Hydrogen Bonds. In The Weak Hydrogen Bond in Structural Chemistry and Biology. Oxford University Press New York, 1999, p. 122. 

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