96
Russ.Chem.Bull., Int.Ed., Vol. 53, No. 1, January, 2004
Voloshin et al.
To make the assignment of the signals, the 13C NMR spectra
were recorded with 1H—13C spinꢀspin decoupling. The IR specꢀ
tra in the range of 400—4000 cm–1 were measured on a Specord
Mꢀ80 instrument in KBr pellets. The UVꢀVis spectra of soluꢀ
tions in CH2Cl2, CHCl3, and DMSO were recorded in the
230—700 nm range on a Perkin—Elmer Lambda 9 spectrophoꢀ
tometer. The plasmaꢀdesorption (PD) mass spectra (detection
of positive ions) were measured on an MS BKh (Selmi) timeꢀofꢀ
flight mass spectrometer. Ionization was induced by 252Cf sponꢀ
taneous decay products (typically, 20•103 decays). Samples
(1—2 mg) were supported onto a gilded disk. The 57Fe Mössbauer
spectra were obtained on a YGRSꢀ4M spectrometer with a conꢀ
stant acceleration mode and collected with a 256ꢀchannel amꢀ
plitude analyzer. The isomeric shifts were measured relative to
sodium nitroprusside. An αꢀFe foil was used for the velocity
scale calibration; 57Co in a chromium matrix, whose temperaꢀ
ture was always maintained at 298 K, was used as the source.
The minimum absorption linewidth in the spectrum of a stanꢀ
dard sample of sodium nitroprusside was 0.24 mm s–1. The
electrochemical characteristics of the complexes were studied
by cyclic voltammetry under anaerobic conditions (dry argon).
A 0.1 M Et4NBF4 solution in CH2Cl2 (salt was preliminarily
dried in vacuo at 100 °C to remove water traces, and then puriꢀ
fied CH2Cl2 was added under argon) was used as the supporting
electrolyte. Electrochemical measurements were carried out acꢀ
cording to a threeꢀelectrode scheme with the use of a glassyꢀ
carbon electrode with a diameter of 0.2 cm as the working elecꢀ
trode, a 1ꢀcm2 Pt plate as the auxiliary electrode, and an Ag/AgCl
electrode as the reference electrode, which was linked to the
solution under study through an electrolytic bridge containing
the supporting electrolyte. The Fc/Fc+ redox couple with the
potential E1/2 = 450 mV relative to this reference electrode was
used as the internal standard. The potentials are given with
respect to the internal redox standard. The potential was conꢀ
trolled using a PI 50.1 potentiostat, and the current was reꢀ
corded on a PUꢀ1 polarograph. The voltammograms were reꢀ
corded on an XY Recorder A3 instrument at potential scan rates
vacuo. The oily residue was dissolved in a 1 : 10 CH2Cl2—hexꢀ
ane mixture, concentrated in vacuo, and kept in a refrigerator
for ∼12 h to grow crystals. The yield was 0.50 g (82%). Found (%):
C, 49.48; H, 6.11; Fe, 5.63; N, 8.25. C42H64B2FeN6O6S6.
Calculated (%): C, 49.51; H, 6.29; Fe, 5.48; N, 8.25. MS,
1
m/z: 1018 [M]+. H NMR (CDCl3), δ: 0.84 (t, 18 H, Me); 1.36
(m, 12 H, CH2); 1.51 (m, 12 H, CH2); 3.29 (t, 12 H, SCH2);
7.39 (m, 6 H, H arom.); 7.80 (m, 4 H, H arom.). 13C{1H} NMR
(CDCl3), δ: 13.5 (s, Me); 21.5 (s, CH2); 31.9 (s, CH2); 33.9 (s,
SCH2); 127.4 (s, CPh); 127.8 (s, CPh); 131.5 (s, CPh); 148.0 (s,
C=N). IR, ν/cm–1: 1504 (C=N); 887, 926, 981 (N—O); 1229
(B—O). UVꢀVis (CH2Cl2), λmax/nm (ε•10–3/L mol–1 cm–1):
273 (12), 309 (7.4), 392 (2.8), 494 (22).
1,8ꢀBis(phenylbora)ꢀ2,7,9,14,15,20ꢀhexaoxaꢀ3,6,10,
13,16,19ꢀhexaazaꢀ4,5,11,12,17,18ꢀhexacaptoprylbiꢀ
cyclo[6.6.6]eicosaꢀ3,5,10,12,16,18ꢀhexaene(2–)iron(2+),
Fe[(Capt)2Gm]3(BPh)2 (2). A solution of Et3N (0.49 mL,
3.5 mmol) in CH2Cl2 (5 mL) was slowly added dropwise with
stirring to a mixture of the Fe(Cl2Gm)3(BPh)2 complex (0.31 g,
0.4 mmol) and captopryl (0.76 g, 3.5 mmol) in CH2Cl2 (5 mL).
The reaction mixture was stirred for 1 h and then a solution of
Et3N (0.49 mL, 3.5 mmol) in CH2Cl2 (5 mL) was added
dropwise. The solution was stirred for 30 min and filtered. The
precipitate, which formed upon the addition of excess hexane
(1 : 5) to the filtrate, was filtered off. Then the filtrate was shaken
with a saturated aqueous solution of oxalic acid to obtain an
additional amount of the complex. The precipitate that formed
was filtered off. The combined precipitates were washed with
water, a small amount of Et2O, and hexane and then dried in
vacuo. The yield was 0.65 g (92%). Found (%): C, 48.75; H, 4.68;
Fe, 3.06; N, 9.44. C72H82B2FeN12O24S6. Calculated (%):
C, 48.87; H, 4.64; Fe, 3.16; N, 9.50. MS, m/z: 1768 [M]+.
1H NMR (DMSOꢀd6), δ: 0.92 (d, 18 H, Me); 1.79 (m,
24 H, CH2CH2); 2.02 (m, 6 H, CH(COOH)); 2.72 (m,
12 H, NCH2); 3.32 (m, 12 H, SCH2); 4.14 (m, 6 H, CH(Me));
7.40 (m, 6 H, H arom.); 7.70 (m, 4 H, H arom.); 12.35 (br.s,
6 H, COOH). 13C{1H} NMR (DMSOꢀd6), δ: 16.3 (s, Me);
24.3 (s, CH2); 36.7 (s, SCH2); 38.2 (s, CH(Me)); 58.3 (s,
CH(COOH)); 128.2 (s, CPh); 131.2 (s, CPh); 148.6 (s, C=N);
171.6 (s, C=O); 173.2 (s, COOH). IR, ν/cm–1: 1510 sh
(C=N); 910 m, 978 (N—O); 1237 (B—O). UVꢀVis (DMSO),
of 5—10 mV s–1
.
1ꢀ(3ꢀMercaptopropyl)silatrane (AtrSH). A mixture of
3ꢀ(mercaptopropyl)trimethoxysilane (18.6 mL, 0.1 mol) and triꢀ
ethanolamine (15 mL, 0.1 mol) was heated in mꢀxylene (150 mL)
with distilling off MeOH. After 4—5 h, the boiling point inꢀ
creased to 140 °C. The solution was concentrated to ∼50 mL and
diluted with nꢀheptane. The glassy precipitate was recrystallized
λ
max/nm (ε•10–3/L mol–1 cm–1): 273 (14), 308 (8.5), 406 (2.8),
500 (23).
1,8ꢀBis(phenylbora)ꢀ2,7,9,14,15,20ꢀhexaoxaꢀ3,6,10,
1
from toluene. The yield was 8.4 g (60%). H NMR (CDCl3), δ:
13,16,19ꢀhexaazaꢀ4,5,11,12,17,18ꢀhexaꢀnꢀoctylthiobiꢀ
cyclo[6.6.6]eicosaꢀ3,5,10,12,16,18ꢀhexaene(2–)iron(2+),
Fe[(nꢀC8H17S)2Gm]3(BPh)2 (3). nꢀOctanethiol (1.17 g, 8 mmol)
was added with stirring to a solution of potassium tertꢀamylate in
THF (30 mL) containing alkoxide (7 mmol) under argon, which
was accompanied by precipitation of a suspension of potassium
nꢀoctanethiolate. The reaction mixture was cooled to –20 °C
with stirring and then the Fe(Cl2Cm)3(BPh)2 complex (0.7 g,
1 mmol) was added. The mixture was stirred for 2 h, warmed to
∼20 °C, stirred for 2 h, heated to 40 °C, and kept at this temperaꢀ
ture for 3 h. The resulting solution was diluted with water and
extracted with CHCl3. The chloroform extract was shaken with
zinc oxide, dried with CaCl2, filtered through a silica gel
SPHꢀ300 (Chemapol) layer (50 mm), and concentrated in vacuo.
The oily residue was washed with MeOH and dried under high
vacuum at 100 °C for 12 h. The yield was 0.68 g (46%).
0.29 (t, 2 H, SiCH2); 1.18 (t, 1 H, SH); 1.54 (m, 2 H, CH2);
2.32 (t, 2 H, SCH2); 2.68 (t, 6 H, NCH2); 3.60 (t, 6 H, OCH2).
13C{1H} NMR (CDCl3), δ: 15.6 (s, SiCH2); 28.0 (s, CH2); 30.1
(s, SCH2); 50.5 (s, NCH2); 57.2 (s, OCH2).
1,8ꢀBis(phenylbora)ꢀ2,7,9,14,15,20ꢀhexaoxaꢀ3,6,10,
13,16,19ꢀhexaazaꢀ4,5,11,12,17,18ꢀhexaꢀnꢀbutylthiobiꢀ
cyclo[6.6.6]eicosaꢀ3,5,10,12,16,18ꢀhexaene(2–)iron(2+),
Fe[(BunS)2Gm]3(BPh)2 (1). A solution of Et3N (0.6 mL,
4.3 mmol) and nꢀbutanethiol (0.53 mL, 5 mmol) in CH2Cl2
(10 mL) was added dropwise with stirring to a mixture of the
Fe(Cl2Gm)3(BPh)2 complex (0.39 g, 0.6 mmol) and CH2Cl2
(20 mL). The reaction mixture was stirred for 1 h, washed sucꢀ
cessively with water and aqueous Na2CO3, and dried with
MgSO4. The resulting solution was filtered through a silica gel
SPHꢀ300 (Chemapol) layer and concentrated to dryness in