Bis- Guanidinium Croconate: Needles
Many organic materials show remnant polarization, which classifies them as ferroelectric. Ferroelectric compounds are able to align their dipoles when an electric field is applied and remain in that alignment when the electric field is removed. All ferroelectric materials are pyroelectric meaning that their polarization is dependent on temperature, and also piezoelectric, meaning they change shape with the application of an electric field. Cocrystals are defined as crystals made of two or more molecules that are packed in three dimensions in a regular manner. Bis-guanidinium croconate, also known as, “Needles” is one of the possible ferroelectrics which will be examined. Crystals of needles were grown and the X-ray diffraction pattern determined. A single unit of “Needles” (one croconate and two guanidines) was extracted from the solved structure in order to be examined. The structure of Needles was analyzed using the computational programs Spartan 16’, Mercury, and Bilbao in search for energy values of different hydrogens bond lengths, direction of the crystal’s dipole, and possible pseudo symmetry. Spartan 16’ was used to perform energy calculations and create an energy profile for each of guanidine’s different hydrogen atoms present. Mercury was used to determine the direction of the crystals; dipole within the structure. The direction of the dipole within the crystal structure was observed where the end with the croconate was more electronegative and the side with the two guanidines was more electropositive. Furthermore, Bilbao was used to determine whether there was any symmetry in the structure of Needles, which determined that there was no psuedosymmetry. However, manual manipulation of the structures showed planes of symmetry along the x, y, and z directions. Crystallization techniques were used to produce Needles. The yellow crystals, bis- guanidinium croconate, were collected to gather information. Fourier-transform infrared spectroscopy (FTIR) was used to run an infrared spectrum and the Melt- Temp was used to test Needles melting point.
"Bis- Guanidinium Croconate: Needles,"
OSR Journal of Student Research: Vol. 5
, Article 345.
Available at: https://scholarworks.lib.csusb.edu/osr/vol5/iss1/345