Molecules 2021, 26, 2280
9 of 13
solid was subjected to a flash column chromatography with Al O (DCM:CH OH; 50:1) to
2
3
3
give 3 as yellow crystals (810 mg; 71% yield).
2,3,7,8,12,13,17,18-Octakis[2-(morpholin-4-yl)ethylsulfanyl]porphyrazinato} magn
{
esium(II) (4): magnesium turnings (45 mg; 1.88 mmol) and iodide (1 crystal) were sus-
pended in n-butanol (15 mL) and refluxed for 6 h in an inert atmosphere. After the reaction
mixture was cooled to room temperature, compound 3 (692 mg; 1.88 mmol) was added and
the mixture was refluxed for 18 h. Next the mixture was filtrated through Celite and the sol-
vents were evaporated with toluene to a dry solid. Crude product was purified by column
chromatography on Al O (DCM:MeOH, 50:1) to give porphyrazine
4
(110 mg; 16% yield)
2
3
◦
as a green-blue solid: mp 113-116 C; R (DCM:MeOH:N(C H ) , 10:1:0.1) 0.42. UV–Vis
f
2
5 3
1
(
DCM): λmax, nm (logε) 375 (4.68), 497 (3.91), 671 (4.71). H NMR (400 MHz; pyridine-d ):
5
δ
H, ppm 2.60 (s, 32H, morph-CH ), 3.11 (s, 16H, CH ), 3.67 (s, 32H, morph-CH ), 4.64 (t,
2 2 2
3
13
J = 10.0 Hz, 16H, CH2). C NMR (100 MHz; pyridine-d5):
δ
C, ppm 33.5; 54.5; 60.0; 67.5;
+
1
41.9; 158.4. HRMS ESI (pos): calc. for C H N O S Mg m/z 1497.5291 [M + H] ; found
64
97 16
8 8
+
m/z 1497.5340 [M + H] .
2,3,7,8,12,13,17,18-Octakis[2-(morpholin-4-yl)ethylsulfanyl]porphyrazinato} zinc(II)
5): dimercaptomaleonitrile (700 mg; 1.9 mmol), Zn(OAc) (175 mg, 0.95 mmol) and
DBU (142 L, 0.95 mmol) in n-pentanol (4 mL) were refluxed in an inert atmosphere for
8 h. Next, the reaction mixture was filtrated through Celite and the filtrate was evaporated
with toluene to dryness. Crude solid was purified by column chromatography with Al O
{
(
3
2
µ
1
2
3
(
1
(
DCM:MeOH; 50:1
→
10:1) to give porphyrazine
5
(90 mg; 12%) as a dark green solid: mp
) 373
H, ppm 2.54–2.63 (m, 32H, morph-
◦
21–123 C; R (DCM:MeOH:N(C H ) , 10:1:0.1) 0.57. UV–Vis (DCM): λmax, nm (log
ε
f
2
5 3
1
4.79); 668 (4.71). H NMR (500 MHz; pyridine-d ):
δ
5
1
3
CH ), 3.09 (s, 16H, CH ), 3.63–3.69 (m, 32H, morph-CH ), 3.81–3.89 (m, 16H, CH ).
C
2
2
2
2
NMR (125 MHz; pyridine-d5): δC, ppm 33.34; 54.37; 59.88; 67.38; 141.92; 157.34. HRMS ESI
+
+
(
pos): calc. for C H N O S Zn m/z 1539.4721 [M+H] ; found m/z 1539.4756 [M + H] .
64 97 16 8 8
3.3. Electrochemical Studies
The electrochemical studies were performed with a Metrohm Autolab PGSTAT128N
potentiostat (Metrohm, Herisau, Switzerland). The data acquisition and storage were
driven by Metrohm Nova 2.1.4 software (Metrohm). The measurements were obtained
2
with the use of a glassy carbon (GC) working electrode (area = 0.071 cm ), Ag wire (pseudo-
reference electrode), and a platinum wire (counter electrode). Before each procedure, the
GC electrode was polished with aqueous 50 nm Al O slurry (purchased from Sigma-
2
3
Aldrich) using a polishing cloth and was subsequently washed in an ultrasonic bath with
deionized water for 10 min to remove inorganic impurities. Ferrocene/ferrocenium couple
+
(
Fc/Fc ) was applied as an internal standard. The solvent (dichloromethane) containing
a supporting electrolyte (0.1 M tetrabutylammonium perchlorate (TBAP)) in a glass cell
(
volume 10 mL) was deoxygenated by purging nitrogen gas for 10 min prior to each
◦
experiment. All electrochemical experiments were carried out at 22 C. The solvent and
reagent were purchased from Sigma-Aldrich Chemie GmbH, Steinheim, Germany.
3
.4. Deposition of Porphyrazines on TiO P25 Nanoparticles
2
Studied porphyrazines were deposited on P25 Aeroxide®® titanium(IV) oxide (TiO2)
nanoparticles using the chemical deposition method [50]. In general, porphyrazine
4 or
5
in the amount of 5 mg was added to a dispersion of 100 mg P25 nanoparticles (sized
approx. 21 nm) in 20 mL of dichloromethane:methanol mixture (1:1, v/v). After the reaction
mixture had been stirred for 72 h, the solvents were evaporated on a rotary evaporator.
Next, the obtained hybrid material was air dried for 24 h. The ratio of the macrocycle to
the P25 TiO was 1:20 (w/w).
2
The hybrid materials were subjected to nanoparticle size measurements using a
Malvern Panalytical NanoSight LM10 instrument (Malvern, UK), equipped with sCMOS
camera, and 405 nm laser. The data acquisition and storage were provided by Nanoparticle
Tracking Analysis (NTA) 3.2 Dev Build 3.2.16 software (Malvern, UK). Throughout, the