110
4 Mechano-Responsive Luminescence via Crystal-to-Crystal Phase …
4.2.1 Synthesis
ZnI•LiCl +
Cl Au C N
Au C N
0 °C, 2 h
THF
1
2
3
A powder of chlorogold(I) isocyanide complex 2 (0.206 g, 0.50 mmol) was placed
in an oven-dried two neck flask. The flask was connected to vacuum/nitrogen manifold through a rubber tube. It was evacuated and then backfilled with nitrogen. This
process was repeated three times. Dry THF (1.0 ml) was then added to the flask
under nitrogen atmosphere. After cooling to 0 °C, organozinc iodide reagent 3 in
THF (0.58 ml, 0.60 mmol, 1.03 M) was added to the mixture dropwise and stirred
for 2 h [8]. The reaction was quenched by addition of a phosphate buffer solution
and then extracted with CH 2 Cl 2 three times and washed with H 2 O and brine. The
organic layers were collected and dried over MgSO 4 . After filtration, the solvent was
removed in vacuo. Further purification by flash column chromatography (SiO 2 , volume ratio of CH 2 Cl 2 /hexane = 1) gave an analytically pure yellowish orange oil 1o
with yellow emission under UV light. (0.186 g, 0.4 mmol, 82%).
1 H NMR (400 MHz,
CDCl 3 , δ): 7.05–7.09 (m, 1H), 7.23 (t, J = 7.6 Hz, 2H), 7.40 (dd, J = 1.6 Hz, 8.0 Hz,
2H), 7.45–7.57 (m, 7H), 7.62 (t, J = 7.6 Hz, 2H).
13 C NMR (100 MHz, CDCl 3 ,
δ): 123.1 (C), 126.2 (CH), 127.3 (C), 127.5 (CH), 128.3 (CH), 128.7 (CH), 128.9
(CH), 129.2 (CH), 131.1 (CH), 131.4 (CH), 136.1 (C), 139.9 (C), 140.4 (CH),
162.9 (CH), 163.5 (C). MS-ESI (m/z): [M + Na]
+ calculated for C 19 H 14 AuNNa,
476.06840; found, 476.06894. Anal. Calcd for C 19 H 14 AuN: C, 50.34; H, 3.11; N,
3.09. Found: C, 50.08; H, 3.00; N, 2.98.
4.2.2 Preparation of 1ch and 1ac from 1o
Pricking 1o to obtain 1ch or 1ac: We perturbed the viscous oil of 1o in a glass vial
using a needle like the following figure, and two or three spots were made through
the procedure. After around 1 h under ambient temperature, small size of crystalline
domain, either 1ch or 1ac, was appeared from the spots and spontaneously developed
to the entire region.
4.3 Single Crystal XRD Analyses of 1ch and 1ac
To investigate the crystal structure of 1ch and 1ac, single crystal XRD of both the single crystal samples were performed. Interestingly, green 1ch crystallized in the chiral
4 Mechano-Responsive Luminescence via Crystal-to-Crystal Phase …
4.2.1 Synthesis
ZnI•LiCl +
Cl Au C N
Au C N
0 °C, 2 h
THF
1
2
3
A powder of chlorogold(I) isocyanide complex 2 (0.206 g, 0.50 mmol) was placed
in an oven-dried two neck flask. The flask was connected to vacuum/nitrogen manifold through a rubber tube. It was evacuated and then backfilled with nitrogen. This
process was repeated three times. Dry THF (1.0 ml) was then added to the flask
under nitrogen atmosphere. After cooling to 0 °C, organozinc iodide reagent 3 in
THF (0.58 ml, 0.60 mmol, 1.03 M) was added to the mixture dropwise and stirred
for 2 h [8]. The reaction was quenched by addition of a phosphate buffer solution
and then extracted with CH 2 Cl 2 three times and washed with H 2 O and brine. The
organic layers were collected and dried over MgSO 4 . After filtration, the solvent was
removed in vacuo. Further purification by flash column chromatography (SiO 2 , volume ratio of CH 2 Cl 2 /hexane = 1) gave an analytically pure yellowish orange oil 1o
with yellow emission under UV light. (0.186 g, 0.4 mmol, 82%).
1 H NMR (400 MHz,
CDCl 3 , δ): 7.05–7.09 (m, 1H), 7.23 (t, J = 7.6 Hz, 2H), 7.40 (dd, J = 1.6 Hz, 8.0 Hz,
2H), 7.45–7.57 (m, 7H), 7.62 (t, J = 7.6 Hz, 2H).
13 C NMR (100 MHz, CDCl 3 ,
δ): 123.1 (C), 126.2 (CH), 127.3 (C), 127.5 (CH), 128.3 (CH), 128.7 (CH), 128.9
(CH), 129.2 (CH), 131.1 (CH), 131.4 (CH), 136.1 (C), 139.9 (C), 140.4 (CH),
162.9 (CH), 163.5 (C). MS-ESI (m/z): [M + Na]
+ calculated for C 19 H 14 AuNNa,
476.06840; found, 476.06894. Anal. Calcd for C 19 H 14 AuN: C, 50.34; H, 3.11; N,
3.09. Found: C, 50.08; H, 3.00; N, 2.98.
4.2.2 Preparation of 1ch and 1ac from 1o
Pricking 1o to obtain 1ch or 1ac: We perturbed the viscous oil of 1o in a glass vial
using a needle like the following figure, and two or three spots were made through
the procedure. After around 1 h under ambient temperature, small size of crystalline
domain, either 1ch or 1ac, was appeared from the spots and spontaneously developed
to the entire region.
4.3 Single Crystal XRD Analyses of 1ch and 1ac
To investigate the crystal structure of 1ch and 1ac, single crystal XRD of both the single crystal samples were performed. Interestingly, green 1ch crystallized in the chiral