Determination of optical activity in monoclinic crystals of tartaric acid, (2R, 3R)-(+)-C4H6O6, using the ‘tilter’ method

The complete optical-gyration tensor for a monoclinic crystal of (2R, 3R)-(+)C4H6O6 has been determined by the tilter method at a wavelength of 680 nm. The tensor components in terms of rotatory power in relation to the principal axes of the indicatrix were found to be ρ◦ 11 = 79(7), ρ◦ 22 = 90(13), ρ◦ 33 = −70(4), ρ◦ 23 = −18(8)◦ mm−1 with ρ = −12.3(1.0)◦ mm−1 in the optic-axis directions. The absolute optical chirality has also been established by combining the structural chirality determination (through the x-ray anomalous scattering) and the signs of the gyration tensor components measured for the same crystal.