X-ray Crystallography Center
The X-ray Crystallography Center was fully renovated in November 2007 and houses two single-crystal X-ray diffraction systems, a brand-new Bruker Kappa APEX DUO diffractometer and a Rigaku HighFlux Homelab diffractometer, providing X-ray diffraction tools for structural characterization of both small molecules (organic, inorganic and organometallic) and macromolecules. X-ray structure analysis of small-molecule are conducted primarily on single crystals submitted by researchers in the department. As an extension service, the facility also accepts sample submissions from other departments within the university and from research organizations outside the university.
Students are encouraged to learn to operate the instrumentation, collect data themselves, and solve their own structures. Practical training, supervision, advice, and assistance are provided by the facility director. The art and science of X-ray crystallography are introduced as a graduate/undergraduate course. Graduate students and post-docs who have completed in-house training may work independently. Undergraduate students generally work directly with the facility director.
Complete X-Ray Crystallography Center Description
1. Small Molecule Diffractometer
The facility maintains a state-of-the-art Bruker Kappa Apex Duo fully automated single crystal diffractometer, duo wavelength system with sealed molybdenum tube and high brightness copper source, first of its kind in New England area. This system can obtain charge density quality data with Mo radiation and exploit all the advantages of Cu wavelength for absolute structure determination and diffraction experiments on ever smaller organic crystals. Low temperature device used is an Oxford 700 series Cryostream system with temperature range of 80-400 K. An Olympus SZ1145 stereo zoom microscope is used to view and mount crystals. The X-ray Crystallographic Facility also includes a Crystal Growth Laboratory, equipped to aid students in obtaining crystals suitable for structure determination.
2. X-ray Photoelectron Spectrometer
An X-ray Photoelectron Spectrometer (XPS) has recently been added to the lab, providing an analyzing tool for surface chemistry. Based upon the photoelectric effect, XPS can measure elemental composition, empirical formula, chemical state, and electronic states of elements. This spectrometer contains a monochromatic aluminum X-ray source with variable spot sizes, a hemispherical analyzer, ion gun, flood gun, high definition camera, and a vacuum system equipped with two turbo pumps and a scroll pump.
The facility has two Dell Precision workstations for data collection, structure solution and refinement. Software packages include APEX2, TWINABS, CELL_NOW, ROTAX, PLATON, WINGX, and a license for the Cambridge Structural Database™ (CSD).
The X-Ray Crystallography Center operates on a 24/7 schedule.
Service is provided for all aspects of small molecule crystallography:
- Sample examination and evaluation (optical and diffraction)
- Data collection and reduction
- Structure solution and refinement
- Presentation graphics preparation
- Preparation of tables and cif files for publication
- File submission to the Cambridge Structural Database™
Turn around time is highly dependent on crystal quality and size.
Key Outputs and Achievements
Boknevitz, K.; Italia, J. S.; Li, B.; Chatterjee, A.; Liu, S.-Y. "Synthesis and Characterization of an Unnatural Boron and Nitrogen-containing Tryptophan Analogue and its Incorporation into Proteins" Chem. Sci. 2019, 10, 4994-4998.
Crockett, M. P.; Tyrol, C. C.; Wong, A. S.; Li, B.; Byers, J. A. "Iron-Catalyzed Suzuki–Miyaura Cross-Coupling Reactions between Alkyl Halides and Unactivated Arylboronic Esters" Org. Lett. 2018, 20, 5233-5237.
Liu, Z.; Ishibashi, J. S. A.; Darrigan, C.; Dargelos, A.; Chrostowska, A.; Li, B.; Vasiliu, M.; Dixon, D. A.; Liu, S.-Y. “The Least Stable Isomer of BN Naphthalene: Toward Predictive Trends for the Optoelectronic Properties of BN Acenes" J. Am. Chem. Soc. 2017, 139, 6082-6085.
Mikus, M. S.; Torker, S.; Xu, C.; Li, B.; Hoveyda, A. H. " Pentacoordinate Ruthenium(ll) Catecholthiolate and Mercaptophenolate Catalysts for Olefin Metathesis: Anionic Ligand Exchange and Ease of Initiation " Organometallics 2016, 35, 3878-3892.
Documents, Manuals, Notes, and Useful Links
- Standard Operation for Beginners
- X-ray Safety Information
- Boston College Radiation Safety
- Request form for crystal structure determination
- Smart Apex User Manual, Bruker-AXS
- Shelx-97 manual, Prof. G. Sheldrick
- CIF file help
- International table of crystallography, full text available on BC library website
- Book: Crystal Structure Refinement: A Crystallographer's Guide to SHELXL, Dr. P. Müller
- Getting crystals Your Crystallographer will Treasure, Dr. R. Staples
- Guide to grow crystals, Dr. J. Reibenspies
- American Crystallographic Association