The 2,4-Pentadienoic acid, with the CAS registry number 626-99-3, is also known as 3,3'-Dinitrobenzidine. Its EINECS number is 210-976-1. This chemical's molecular formula is C₅H₆O₂ and molecular weight is 98.1. What's more, its IUPAC name is (2E)-penta-2,4-dienoic acid. You should not breathe dust. When using it, you must avoid contacting with skin and eyes. It is stable at common pressure and temperature, and it should be sealed and stored at the temperature of -20 °C. 

Physical properties of 2,4-Pentadienoic acid are: (1)ACD/LogP: 0.82; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -0.25; (4)ACD/LogD (pH 7.4): -2.05; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 5.69; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 2; (10)#H bond donors: 1; (11)#Freely Rotating Bonds: 2; (12)Polar Surface Area: 26.3 Å²; (13)Index of Refraction: 1.474; (14)Molar Refractivity: 26.56 cm³; (15)Molar Volume: 94.4 cm³; (16)Polarizability: 10.52×10^-24cm³; (17)Surface Tension: 34.6 dyne/cm; (18)Density: 1.039 g/cm³; (19)Flash Point: 121.5 °C; (20)Enthalpy of Vaporization: 49.73 kJ/mol; (21)Boiling Point: 215 °C at 760 mmHg; (22)Vapour Pressure: 0.0586 mmHg at 25°C.

Uses of 2,4-Pentadienoic acid: it can be used to produce penta-2,4-dienoic acid methyl ester by heating. It will need reagent H₂SO₄.

You can still convert the following datas into molecular structure:
(1)Canonical SMILES: C=CC=CC(=O)O
(2)Isomeric SMILES: C=C/C=C/C(=O)O
(3)InChI: InChI=1S/C5H6O2/c1-2-3-4-5(6)7/h2-4H,1H2,(H,6,7)/b4-3+
(4)InChIKey: SDVVLIIVFBKBMG-ONEGZZNKSA-N