2-(2′-Hydroxyphenyl)benzimidazole is the most widely studied excited-state intramolecular proton transfer (ESIPT) molecule with normal and tautomer emissions. 2-(2′-Hydroxyphenyl)benzimidazole has been used as a fluorescent probe in various systems.

Physicochemical Properties

Molecular Formula	C13H10N2O
Molecular Weight	210.23
Exact Mass	210.079
CAS #	2963-66-8
PubChem CID	18075
Appearance	Light yellow to yellow solid powder
Density	1.289g/cm3
Boiling Point	388.6ºC at 760mmHg
Melting Point	239-243ºC
Flash Point	167.6ºC
Vapour Pressure	0mmHg at 25°C
Index of Refraction	1.726
LogP	2.935
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	1
Heavy Atom Count	16
Complexity	246
Defined Atom Stereocenter Count	0
InChi Key	XWXMGTIHBYFTIE-UHFFFAOYSA-N
InChi Code	InChI=1S/C13H10N2O/c16-12-8-4-1-5-9(12)13-14-10-6-2-3-7-11(10)15-13/h1-8,16H,(H,14,15)
Chemical Name	2-(1H-benzimidazol-2-yl)phenol
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

References

[1]. Excited state proton transfer of 2-(2'-hydroxyphenyl)benzimidazole and its nitrogen substituted analogues in bovine serum albumin. Photochem Photobiol Sci. 2014 Sep;13(9):1297-304.

Solubility Data

Solubility (In Vitro)

DMSO: 100 mg/mL (475.67 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (11.89 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (11.89 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	4.7567 mL	23.7835 mL	47.5670 mL
	5 mM	0.9513 mL	4.7567 mL	9.5134 mL
	10 mM	0.4757 mL	2.3783 mL	4.7567 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.