I already got a reference stating the values of most solvents, but not including glycerol and N-methylformamide. I'd appreciate if you could help in this matter.
I'm not sure whether this is what you mean, but here's paper that classifies a variety of solvents according to two parameters that --as far as I understand-- largely reflect polarity and polarizability. Maybe it can help you.
R. Carlsson, T. Lundstedt, C. Albano, Acta Chem. Scand., Ser. B, 1985, 39, 79–91.
Sure. The paper is entitled "Screening of Suitable Solvents in Organic Synthesis. Strategies for Solvent Selection." The DOI number is: 10.3891/acta.chem.scand.39b-0079. Here's a link to the journal issue where the paper is in: http://actachemscand.dk/volume.php?select1=5&vol=391
Although that paper is interesting and does list many liquids. Glycerin (glycerol) does not appear in the list. So this appears to be an open question yet. If someone finds the actual value, I too would like to see it.
You can find the answer in the following references;
I you are not, please wirte me.
[] C. Reichardt, Solvents and Solvent Effects in Organic Chemistry, Third Edition. WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, 2003.
[] M.J. Kamlet, J.-L. Abboud, M.H. Abraham, R.W. Taft, Linear Solvation Energy Relationships. 23. A Comprehensive Collection of the Solvatochromic Parameters, π*, α, β, and Some Methods for Simplifying the Generalized Solvatochromic Equation, Journal of Organic Chemistry 48 (1983) 2877-2887.
[] M.J. Kamlet, J.L. Abboud, R.W. Taft, The Solvatochromic Comparison Method. 6. The π* Scale of Solvent Polarities, Journal of The American Chemical Society 99(18) (1997) 6027-6038.
[] Y. Marcus, The Properties of Organic Liquids that are Relevant to their Use as Solvating Solvents, Chemical Society Reviews 22 (1993) 409-416.
[] J. Catalán, Toward a Generalized Treatment of the Solvent Effect Based on Four Empirical Scales: Dipolarity (SdP, a New Scale), Polarizability (SP), Acidity (SA), and Basicity (SB) of the Medium, Journal of Physical Chemistry B 113 (2009) 5951-5960.