Molecular Switches

X

X

O

O

405 nm

	N	O		N	O
	Me		Vis
		O		Me	O

3E: X = H	3C: X = H (λmax in toluene: 584 nm)
4E: X = SMe	4C: X = SMe (600 nm)
5E: X = OMe	5C: X = OMe (625 nm)
6E: X = NMe2	6C: X = NMe2 (673 nm)

M

M

Me	Me N	Me
Me N		800 nm
	O 405 nm	O (read)
	(write)
N	O	O

	Me	O		N
			554 nm	Me	O
		6E		6C
	(λmax 404 nm)		800 nm	(λmax 673 nm)
	H+	–H+		H+	–H+
H	Me		H	Me
N+			N+
Me		O	Me		O
			405 nm
		O	(write)
	N				O
	Me	O		N
			554 nm	Me	O
	6EH		(erase)	6CH
	(λmax 370 nm)			(λmax 554 nm)

	10000
	(4)
	(3)	(2)
			(1)
ε	5000
	0
	300	500	700	900
	Wavelength/nm

M

M

	O
	O	O	UV
			n
	N
Me	O	O		N
			UV
	O			Me
			Vis

O

	O	O
	O	n
		O

O

7E: n = 1 8E: n = 2 9E: n = 3

7C: n = 1 8C: n = 2 9C: n = 3

		O					O
	O				320 nm		O
		O					O
							N
	N
S		O	O	N	520 nm	S	O	O	N
							O
	O
		10E					10C

Donor	E–form	Acceptor	Donor	C–form	Acceptor

Energy

hν

F V

F V

R O R O

	N	O	N	O
	Me	UV		OO
		OO	Me
		Vis, UV
	11E: R = nPr		11C: R = nPr
	12E: R = iPr		12C: R = iPr

M

F V

	300
Intensity	200
	100
	0
	0	6 0	12 0	180	240	30 0
			Time/min

M

Me	O		Me	O
N 2	O	UV	N	O
3
		Vis
R	O			O

13E: R = H	R
	13C: R = H
14E: R = OMe	14C: R = OMe
15E: R = Me	15C: R = Me
16E: R = Cl	16C: R = Cl
17E: R = F	17C: R = F

O		O		O	O		O	O	O	O
	O		UV					∆
O		O					O			O
	O		O					O
O					O				O
		O		O		H	O	O		H O
		18E				18C				19

M

	O		O
O	O	O	O
		Enantiomer
	O		O
(P)–2E		(M)–2E
UV	Vis	UV	Vis
	O		O

7a	O
	Enantiomer
O

O

O

O	O
(7aS)–2C	(7aR)–2C

M

S

20Z

			O		O
	O	UV		UV
			O		O
		S
					S
	O	UV		Vis, UV
			O		O
	O	20E			20C

	O	O
	O	O
O		O
	O	O
21E		21E-TS

M

	O		O
	O	N	O
		Me
	N		O
Me	O
	(P)-22E	(M)-22E

		1
	bance						M 0 M
		0,5
	bsorA
		0
		300	400	500	600	700	800
				Wavelength/nm

M M

	20
	10
			(1)
	0
		(2)
	- 10
	3 0 0	4 0 0	5 0 0	6 0 0
		Wavelength/nm

O

		CH2
	O	N C6H12 O2C C R1
		x
		O

CH2

R2

O2C

O

C6H12 O2C

C

R1

y

23:R1 = H, R2 = CN

24:R1 = Me, R2 = OMe

F

V

O

S O

O

25E O O

n-C5H11CN

(R)–27

26 (5CB)

>

	16
	12
m
/
Pitch	8
	4
	0
	0	2	4	6

Cycle/Times

M 0 M

0 M 0 M

O

S N

NHR

O O

28E: R = Concanavalin A

30E: R = α–Chymotrypsin

OH

HO

HOHOO

O

NO2

29