High-resolution Electrospray ionization mass spectroscopy (HR-ESI-MS)

We offer a collaboration using HR-ESI-MS using LTQ Orbitrap XL of Thermo Fisher Scientific (Resolution: ~ 100,000, Ionization methods: ESI, APCI, etc.). Because of high mass accuracy (less than 3 ppm), we can identify POM species present in solution.

Fig. 1 shows ESI-MS spectra of (Bu₄N)₄[PW₁₁VO₄₀] dissolved in CH₃CN. We observe the desired profiles of [PW₁₁VO₄₀]^4-, H[PW₁₁VO₄₀]^3-, and (Bu₄N)[PW₁₁VO₄₀]^2-.

Fig. 2 shows ESI-MS of a mixture of Cs₆[γ-SiW₁₀O₃₆Ru(C₆H₆)] and Cs₅[γ-SiW₁₀O₃₆Ru(C₆H₆) Ru(C₆H₆)Cl] dissolved in H₂O-CH₃CN solution. Both 1:2 and 2:2 complex of [Ru(C₆H₆)]²⁺ and [SiW₁₀O₃₆]^8- are detected confirmed by ESI-MS (Euro. J. Inorg. Chem. 2018, 2018, 1778-1786.)

Single Crystal X-ray diffraction

We offer a collaboration by means of single crystal X-ray diffraction with synchrotron radiation.

The following two beamlines are availabe:

1. BL02B1 beamline @ SPring-8 in Japan http://www.spring8.or.jp/ja/

Detector: PILATUS3 X CdTe 1M, Diffractometer: RIGAKU 1/4-chi goniometer (4-axis motor drive), Data reduction: Rapid Auto or CrysAlisPro, Wavelength: 0.4248 Å (fixed), Temperature 100 K~ 400 K

2. 2D beamline @ Pohang Accelerator Laboratory (PAL) in South Korea http://pal.postech.ac.kr/paleng/

Detector: Rayonix MX225HS CCD area detector, Diffractometer: single-axis motor drive, Data reduction: HKL3000 or CrysAlisPro, Wavelength: 0.600~0.900 Å (variable), Temperature 100 K~ 400 K

Shorter wavelength (higher energy) X-rays reduce the effect of X-ray absorption by heavy elements such as W, Pt, Au, Ln and so on, which improves the determination of the parameters of lighter elements such as C, N, and O in a crystal structure. We can collect high quality data with high resolution, which is essential for the determination of severely disordered structures, solvent molecules and counter ions. Low divergent synchrotron radiation gives sharp peak separations even for large unit cell crystal systems. One data collection requires only 5∼15 min on average, which allows us to monitor dynamic structural change under external stimuli (UV light, temperature, and chemical reagent).

Recently we successfully determined the first example of self-assembly of cyclic hexamers of γ-cyclodextrin in the hexagonal cavities of metallosupramolecular framework. More than 700 independent atoms in an asymmetric unit were refined from the data collected at 2D beamline in PAL. Monoclinic C2, a = 48.570(8) Å, b = 28.050(8) Å, c = 52.051(10) Å, β = 97.93(4), V = 70235.6 Å3, R1 = 8.09 %. (Chem. Sci. In press. DOI: 10.1039/D0SC03925J)

Also, we determined the 3D porous metallosupramolecular framework having nanometre-sized open channels with a very high porosity of 78% from the data collected at BL02B1 beamline in SPring-8. Cubic I213, a = b = c = 41.407(3) Å, V = 70993.9 Å3, R1 = 4.79 %.

We observed stepwise single‐crystal‐to‐single‐crystal (SCSC) transmetallations from Cd²⁺ to Cu²⁺ in a 116‐nuclear metallosupramolecular cage‐of‐cage. We successfully determined the severely disordered two parts in a 1:1 ratio. Cubic F432, a = b = c = 77.9224(2) Å, V = 473137 Å3, R1 = 5.72 %. (Chem. Eur. J., 2020,26, 1827-1833. DOI: 10.1002/chem.201904275))

Every year we have three or four opportunities to conduct synchrotron experiments. Please send a message to the following contact persons.

Contact Person:

Tatsuhiro Kojima, Department of Applied Chemistry, Kobe City College of Technology (KCCT), tkojima@kobe-kosen.ac.jp;

Masahiro Sadakane, Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, sadakane09@hiroshima-u.ac.jp