実験報告書様式（一般利用課題・成果公開利用）（ ※本報告書は英語で記述してください。ただし、産業利用課題として採択されている方は日本語で記述していただいても結構です。 ）MLF	 Experimental Report

提出日 Date of Report

課題番号 Project No.

装置責任者 Name of responsible person

2014A0163

Prof. Yasuhiro Miyake

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Preciseanalysisofelectronic

structureof

thelocalized

D1

P-heterocyclic singlet biradical

実施日 Date of Experiment

実験責任者名 Name of principal investigator

2014.11.18-19

Shigekazu Ito
所属 Affiliation
Department of Applied Chemistry, Tokyo Institute of Technology
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
1-Benzyl-3-t-butyl-2,4-Bis(2,4,6-tri-t-butylphenyl)-1,3-diphosphacyclobutane-2,4-diyl (abbreviated as BR)
C49H74P2, pellet of powdered sample
Molecular formula:
tBu
P

tBu

tBu

tBu

tBu

PCH 2tBu

tBu

tBu = C(CH3)3

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

The BR sample was compressed as a pellet (20 mmø, 2 mm width) and attached to the center of the detectorof MLF D1 muon beam-line.
beam.

The position of sample was checked by the preparative irradiation of muon

Next the level crossing resonance (LCR) experiments were carried out in order to determine thepresence of muonium species preliminary.

The experimental conditions were as follows:

1) Temperature = 300 K, Blongitudinal = 0 to 400 mT2) Temperature = 200 K, Blongitudinal = 0 to 200 mT
In the experiment under the conditions 2), temporary stops of the beam accumulated, and scans from 200 mT
to 400 mT were not carried out.
12. 実験方法及び結果（つづき） Experimental method and results (continued)
Results
Condition 1)

The lost asymmetry in TF measurement recovers full at relatively low magnetic field of 100 mT, suggestingthat the Mu radicals may see relatively small effective magnetic field.

DFT calculationｓ (UB3LYP/6-31G*)

for the simplified model molecules suggested that the putatively predominant C-muoniated species would
show the hfc parameters of 17 MHz.

Indeed the observed data might be consistent to the theoretically

predicted results, but characteristic resonance could not be observed in this experiment.
species would be observed under the magnetic field of 50-100 mT.

The muonium

On the other hand, the alternatively

possible P-muoniated species would show hfc of 100 MHz, but the characteristic resonance was notdetermined.
Condition 2)
The measurements at 200 K gave almost the same
spectrum as the case of 300 K, and no obvious resonancesignal was characterized.

Because of limit of experimentperiod, the attempted measurement with the magnetic fieldof 200-400 mT was not carried out.

Both of the measurements at 300 K and 200 K might not
be suitable for characterization.

Motion of the molecules

was minimized at these temperatures, and width of theresonance peaks might be considerably large.

Therefore,

the measurements at the higher temperatures would be suitable to observe the characteristic resonances ofthe muonium species.
2