Mr. Rakovsky,

Are they exsist or not, please pay attentiuon on the attached only few examples and related refs. [a]-[d] below.

1. In the shown structure of ref. [b] the r(CH...O) is 3.557A and the ange is about 135o. So that this interaction cannot described as real one. For this reason we are not discussed it in the paper.

2. In the shown structure to refs. [a] and [c] the distances are within 3.193-3.28A, but the CHO angles are at about 125o. So that these interactions could be described using the common term 'short contacts'

3. In ref. [d] however the CHO distance is rather for moderate-to-week H-bonding 3.09A) an the CHO angle is near to 180o. For this reason even in the paper we are discussed such interaction type even as 'H-bonding', in spite, fact that it is not in the terms of the classical H-bonding.

So there are only few examples of CH...X interactions shown. Accounting for that we have more than 350 examples of crystals and in phenyl containing counterions oft are found such non classicxal H-bond interactions encompassing points 1-3.

Hello :)

I haven't any problem with the existence of these interactions, I am only searching one very well written article ;)

[It is somewhat resembling one "historical" (or, better, hysterical) discussion of my former colleaugues a couple of years ago. There was also a reference to similar discussion about other topic, I think what we called "bond-stretch isomerism" (it was mainly unrecognized substitutional disorder).]

forgot...refs.

[a] Ivanova, B.; Spiteller, M. (2010) Organic mandelates as promising materials with non-linear optical application, Structural Chemistry, 21, 989-993

[b] Ivanova B., Spiteller M. (2013) Factors stabilizing the gas-phase ionic species of crystals of organic salts – Experimental and theoretical study, Journal of Molecular Structure, 1036, 226–234

[c] Bojidarka B. Ivanova, Michael Spiteller, Physical optical properties and crystal structures of organic 5-sulfosalicylates – Theoretical and experimental study, Journal of Molecular Structure 1003 (2011) 1–9

[d]. T. Kolev, R.Seidel, B.Koleva, H. Mayer-Figge, M. Spiteller, W.Sheldrick, Polymorphs of 4-(dihydroxymethyl)pyridinium hydrogensquarate – Crystal structures and spectroscopic properties, Journal of Molecular Structure 931 (2009) 45–49

It is really a disputable question because as you can read there have crystal examples where it is diffucult to clasify the given CH...X as 'short contact# But there have examples where due to the crystallographic packing thhey have very close parameters to the pure H-bonds in classical terms.

A mystery is solved, it is (very nicely written indeed!) article of Joel Bernstein from Crystal Growth & Design's virtual special issue in honor of our great guru G. R. Desiraju :)

http://pubs.acs.org/doi/abs/10.1021/cg301519k