By: Chris Seyun Jeong

Nurul Eisha currently works as a Laboratory Assistant in the Department of Chemistry at Fordham University. He is performing research in structural inorganic chemistry with Dr. Peter Corfield, Lecturer in Fordham University’s Department of Chemistry. Eisha is a Biology major in the class of 2023 at Fordham University’s Rose Hill campus and aspires to have a career in the medical field as a physician or a surgeon. His extracurricular activities are emblematic of his career plans, from his experience as an EMT in Fordham’s emergency medical care organization (FUEMS) to his ongoing pursuit of the completion of ambulance training. He initially reached out to Dr. Corfield to be proactive during the pandemic shutdowns. Eisha chose to reach out to Dr. Corfield because he was previously a student in his General Chemistry course. Eisha began work in the lab in the summer of 2021. 

Although Eisha first became a lab assistant during the summer, Dr. Corfield’s work on crystallography has been taking place for several years now, with some of his Fordham publications dating back to 2013. Dr. Corfield specializes in X-ray crystallography, a field that involves the determination of the detailed structure of chemical compounds by diffraction of X-rays by the organized array of atoms and molecules in a crystal.  It is common for chemistry labs to be equipped with intricate technologies, and Dr. Corfield’s lab is no exception. The instrument used specifically for x-ray crystallography is a 50-kilovolt machine that diffracts X-rays by a crystal.

Dr. Corfield’s students work at making new inorganic compounds that contain copper cyanide and various organic bases, altered to form their conjugate acids. In these compounds, the copper cyanide part forms a variety of intricate two- or three-dimensional networks, and the altered bases sit in cavities within these networks. Dr. Corfield has previously worked with numerous students whose work with crystalline structures are showcased in vials in the lab. Eisha began work by assisting with separations as a means of acquiring laboratory skills. On September 30^th of this year, he began his first synthesis, in which he used the base 2-(ethylamino)ethanol (etoenH). He first mixed the base with nitric acid (HNO₃) to produce the conjugate acid. Eisha used nitric acid instead of the previously used hydrochloric acid (HCl), because chloride ions from the HCl can interfere with the formation of the structure. By using nitric acid, Eisha is hoping that there will be no interference. It typically takes several days to complete a synthesis, but there are instances where several weeks are required. Eisha’s prep first produced a sparse number of crystals within a week, prompting him to analyze their chemical interactions while he awaited the further growth of crystals. He repeated the same prep with a variation of proportion between molecules in the chemical mixture to determine if it would alter the structures in products. His latest preparations from October 27^th involved the synthesis of roughly half millimeter-sized gold/brown crystalline products, suitable for further analysis by X-ray methods. Following formation of any crystals, lab members and Dr. Corfield first check the literature to either confirm or deny that they have developed a new compound. In Eisha’s case, it was shown that this was a new compound, and its structure is currently being analyzed by X-ray diffraction.

Infrared spectroscopy, an important focus of the lab, utilizes infrared radiation that interacts with chemicals by absorption, which highlights the nature of specific interactions between atoms, such as bonds. The infrared spectrum’s y-axis indicates the percent of transmittance and wavenumbers correspond to the x-axis. Transmittance refers to the passing of light through the structure in study and wavenumber is proportional to the frequency of the wave.

In the case of Eisha’s new compound, the infrared spectrum highlighted appearances of cyanide (at about 2100 cm^-1) and other functional groups, marked by absorbing an incoming light emitted by the machine at a particular frequency. The IR graph also exhibited a strong peak at approximately 1700 cm^-1 and some peaks around 3200 cm^-1, indicating the appearance of oxazole compound in the structure; Oxazole is a ring product that unexpectedly formed during the synthesis. Nevertheless, it was possible to correlate the infrared spectrum with the structure obtained by the X-ray analysis.

Each of the five students in Corfield’s lab develops a synthesis of their own compound. There is an ongoing cycle of X-ray data collection after each successful synthesis of a crystalline product because the purpose of the labs is to identify new types of structures and classify them. The complement goal involves developing the ability to predict what new structures would look like.

As one of the purposes of the lab is to develop a new type of crystalline structure, it is common for Dr. Corfield to examine work from research databases to ensure the originality of a crystal structure at hand. Finding absolute originality would be an exciting feat, and such accomplishments have already been made in the lab. There have been around 25 to 30 new structures developed and characterized over the course of Dr. Corfield’s research lab. Nurul Eisha, although just beginning as a lab assistant, hopes to continue his work with Dr. Peter Corfield’s crystallography lab and aspires to make groundbreaking contributions. From there, he can use the experience as a springboard toward his career aspirations in the medical field.