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Ion-Selective HydrazoneЦAzine Tautomerism of a 14-Membered Macrocylic Ligand.

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Z e : ' H NMR (300 MHz. CDCI,. 25 C. TMS): 6 =1.22 (s, 9 H ; CMe,),
1.40 (virt. t. J = 4.3 Hz, 1 8 H ; PMe,). 6.9-7.8 (m. 15H; Ph, SiPh,);
"C NMR (CDCI,, 25 "C): 6 = 211.9 (PhCCO), 225.3 (PhCCO), 233.3
(CO): 1R (CH,CI,): ? [cm-'1 =I943 (s. CO), 1649 (w, CCO).
(121 J. M. Jenkins. B. 1 . Shaw, J. Chum. Suc. / A ) 1966. 1407.
113) Crystallographic data for Za and 2c. 2 a : C,,H,,CI,O,P,W, M = 553.06,
P2,;/7(No. 14), N = 8.668(2), b = 25.76(1), c = 9.541(4) A.8 =102.79(4)".
V = 2078(3)
Z = 4. pcAlcd
= 1.768 gcm-3. ;i(MoK,) = 60.93 cm-'.
1533 unique observed reflections. 3 ' < 2 8 < 47.9-, R = 0.029, R, =
M = 687.19. PcrrZ,(No. 29). u =15.584(1),
0.037. 2 c : C,,H,,CI,O,P,W,
h =12.599(1). r =13.962(1)A, fl=90.0', V = 2741.3(1)A3, Z = 4 ,
pEalcd
=1.665 gem-', p(Mo,,) = 46.40 em-', 2206 unique observed reflections. 3" < 2 8 < 60". R = 0.035. R, = 0.034. All intensity measurements were made at room temperature, using Mo,, radiation (graphite
monochromator, 2. = 0.71069 A), and a variable-rate, 0-20 scan technique. Empirical absorption corrections were applied. The structures were
solved by conventional heavy-atom methods and refined by the full-matrix
least-squares method. All calculations were performed using the TEXRAY
programs. For 2c, both enantiomers were examined. Further details of the
crystal structure investigations can be obtained from the Fachinformationszentrum Karlsruhe, GeSelkChdft fur wissenschaftlich-technische Information mbH. D-W-7514 Eggenstein-Leopoldshafen 2 (FRG), by quoting the depository number CSD-56078. the names of the authors, and the
journal citation.
1141 a) D.C. Brower. K. R. Birdwhistell, J. L. Templeton. OrgunomefallicJ
1986. 5. 94; b) W. J. Sieber, M. Wolfgruber. N . H. Tran-Huy, H. R.
Schmidt, H. Heiss. P. Hofniann, F. R. Kreissl. J. Orgumme/. Chrm. 1988,
340. 341
(151 D. Mootz, J. Hocken, A n p i , . Cliem. 1989. 101, 1713: A n g w . Chem. Int.
Ed. Engl. 1989. 28, 1697.
[16] E . 0. Fischer. P. Friedrich, A n g r x Chem. 1979, 91, 345; Angew. Chem.
Int. Ed. Engl. 1979. 18, 327.
[17] J. A. K. Howard, J. C. Jeffery, J. C. V. Laurie, I. Moore, E G. A. Stone, A.
Stringer, Inorg. Chin?.Arfu 1985, 100, 23.
[18] P. J. Stang, M. Boehshar, H. Wingert, T. Kitamura, J. Am. Chem. SOC.
1988, 110, 3272.
1191 K. A . Belsky. M. F. Asaro. S . Y. Chen. A. Mayr. Organometullics, in press.
CDCI, is consistent with the apparently unique bis(viny1hydrazone) structure shown in 1a rather than the expected
bis(azine) tautomer 1 b. The resonance of the vinyl protons is
observed at 6 = 6.0, and the downfield shift of the internal
NH protons (6 = 3 4.3) Is consistent with their intramolecular
hydrogen bonding to the transannular pyridine nitrogen
atoms. Addition of trifluoroacetic acid to the CDCI, solution apparently gives 1 . 2H' since the vinyl proton resonances are no longer observed and the acidic protons give a
broad resonance centered at 6 = 19. As suggested by the
presence of enamine moieties in structure 1 a, DDQ selectively aromatizes two rings of 1 to give bis(ary1hydrazone)
macrocycle 4, which still possesses two internal hydrogens
(6 = 17.6).
Q&jfk
Ion-Selective Hydrazone-Azine Tautomerism of a
14-Membered Macrocylic Ligand **
By Thomas W Bell* and Andrew 7: Papoulis
Bridged pyridine ligands,"' including torands,[21are versatile complexing agents for metal ions. In the course of
current efforts to incorporate pyrrole rings into torands using the Piloty rearrangement of a ~ i n e s , 'we
~ ] have discovered
a novel 14-membered azamacrocycle 1. The binding of lithium and the smaller alkaline-earth metal ions by this ligand
is accompanied by pronounced changes in its UVjVIS absorption characteristics. Ion-selective optical sensors based
on metal complexation are of current interest for analytical
application^.'^]
Macrocyclic ligand 1 was synthesized in two steps from
9-n-butyl-2,3,7,8-tetrahydro-l
H,6 H-acridine-4,s-dione 2['l
(Scheme 1). Slow addition of 2 to a large excess of hot
methanolic hydrazine gave (E,Z)-dihydrazone 3 as a yellow
precipitate. Condensation of diketone 2 with dihydrazone 3
in hot methanol gave macrocycle 1 as a yellow-orange solid
in 38-47 O h yield with most methods of addition of the reactants. However, when higher dilution was achieved by simultaneous, slow addition of 2 and 3 to hot methanol, 1 was
produced in 82% yield. The ' H N M R spectrum of 1 in
9
fi
tt"Mg2+#
f l H H'#
32
1 *2H'
lb
la
;
4
1 . Mg2+
Scheme 1. a:Hydrazine, MeOH ( 5 5 % ) ; b:MeOH (82%); c:Dichlorodicyanobenzoquinone (DDQ), toluene (63%); d:Mg(NO,), .6H,O, CH,CN (33%).
Macrocycles 1 and 4 both contain 14-membered rings with
four of the six nitrogen atoms in the correct positions to
coordinate metal ions. To do this 4 must either lose the
internal protons or tautomerize to the bis(azo) form, whereas I should readily form metal complexes by tautomerization
to the bis(azine) form 1b. Thus 1 reacts with Mg(NO,), in
CH,CN to form 1 Mg(NO,), , which was isolated as a yellow solid. FAB-MS, 'H NMR, 13C NMR, and FT-IR data
are in keeping with the C, symmetric structure. Apparently
1 . Mg(NO,), does not possess a horizontal mirror plane,
since two-proton multiplets are observed in the 'H NMR
spectrum at 6 = 2.8 and 3.3 displaying geminal coupling
( J = 17 Hz). This featuie suggests that 1 exists in a puckered
conformation in the complex, possibly due to axial coordination of Mg2+ by NO; on only one face. Ring methylene
1
[*] Prof. T. W. Bell, A. T. Papoulis
Department of Chemistry, State University of New York
Stony Brook, NY 11794-3400 (USA)
[**I
This work was supported by the National Institutes of Health (PHS grant
GM 32937). The 600 MHz spectrometer was purchased with funds from
the National Institutes of Health (RR05547A), the National Science
Foundation (CHE 891 1350), the Center for Blotechnology, and the State
University of New York, Stony Brook.
Angrw Chem. Int. Ed. Engl. 31 (1992) N o . 6
0 VCH VeriugsgrseN.sLhufi mhH. W-6940 Weinhrim, I992
0570-0833j92/0606-0749 $3.50+ ,2510
749
protons of 1 thus serve as stereochemical probes which are
absent in reported complexes of bis(azine) macrocycle 5.[6s
71
Tautomerism of l a to l b during complexation produces
dramatic changes in the UV-VIS absorption spectrum of the
ligand. Figure 1 shows that the largest change is the disappearance of the absorption band at 1,, = 380 nm upon
complexation of Mg2+.The spectra shown in Figure 1 were
+
0.75 1
300
LOO
h lnml
Experimental Procedure
500
Fig. 1. Overlayed plots of the UVjVIS spectra of 1 and 1 . Mg(NO,), in
M). Wavelengths in nm; A = absorbance.
CH,CI, (1.9 x
obtained from dissolved samples of 1 and 1 . Mg(NO,), in
CH,CI, . The same spectroscopic changes were observed
when solid Mg(NO,), . 6 H,O was added to a solution of 1
in CH,Cl,. To test the selectivity of 1 in extractions, solutions of 1 in CH,Cl, were exposed to alkali-metal and
alkaline-earth nitrates and chlorides. We followed the complexation by measuring changes in the ratio of absorbances
at i= 380 and 265 nm (the isosbestic point). The results of
this study (Fig. 2) show that the optical response is selective
for small cations of high charge density such as Li', Mgzi,
and Ca2+.It is not clear why the nitrate and chloride salts of
individual cations respond differently, but this effect may be
related to solubility differences in CH,CI,. Anion effects on
the stability of crown ether complexes and on the extractability of salts from aqueous into organic solution have been
observed.[']
100 r
1
ao
60
3: A solution of 1.O g (3.7 mmol) of diketone 2 [S] in 50 mL of methanol was
added dropwise over 3.5 h to a rapidly stirred, boiling solution of 3.5 mL (3.6 g,
I10 mmol) of anhydrous hydrazine in 50 mL of methanol. The resulting yellow
solution was heated at reflux under N, for 30 min, then cooled to room temperature. Methanol was removed under vacuum, and 100 mL of water was added
to the residue. The resulting mixture was extracted with CHCI, (3 x 50 mL),
and the combined extracts were dried over Na,SO, and concentrated. Ethyl
acetate was added, producing a yellow precipitate, which was allowed to stand
at 5 "C for several hours and was then collected by vacuum filtration. Drying
in vacuo gave 0.61 g (55%) of 3 as a light yellow solid. M.p. 175-192°C
(decomp.). 'H NMR (300 MHz, CDC1,): S = 0.96 (t. ,J(H,H) = 6.6 Hz, 3 H ;
CH,), 1.42 (m, 4 H ; CH,CH,CH,). 1.96 (m, 4H: H2. H7), 2.53-2.64 (m, 6H:
H ~ , H X , A ~ C H , ~ P ~ ) , ~ . ~ ~ ( ~ , ~ H ; H ~ .=HNNH2),8.7(br
~),~S(S,~H;(E)C
S, 2 H ; (Z)C = NNH,); I3C NMR (75 MHz, CDCI,): 6 =149.0, 147.5, 145.9,
145.3, 135.8, 131.5.130.4, 33.7,30.7,28.2,26.5, 24.9, 23.6,23.0,22.9.20.9,13.7.
FT-IR (KBr): 5 [cm-']= 3355 s (NH,), 3273 m (NH,), 3192 m (NH,), 2935 s
(CH), 2912 s (CH), 2842 s (CH), 1634 m (C = N). MS (70 eV): m / z 299 ( M I ,
13), 211 (100%). Correct C,H,N-analysis.
1: Separate solutions of 50 mg (0.18 mmol) of 2 and 55 mg (0.18 mmol) of 3 in
30 mL of methanol were added dropwise over 5 h to 20 mL of rapidly stirred,
boiling methanol. The resulting mixture was heated at reflux under N, for 14 h,
then cooled to room temperature. The precipitate was collected by filtration,
washed several times with methanol, and dried in air to give 80 mg (82%) of 1
as a yellow solid. M.p. 190°C (decomp.). ' H NMR (300 MHz. CDCI,):
6 = 0.98 (1. 'J(H,H) = 6.6 Hz, 6 H ; CH,), 1.47 (m, XH; CH,CH,CH,). 2.01
(m. 4 H ; H2), 2.50 (m, 4H, H7). 2.67 (t. ,J(H,H) =7.2Hz, 4 H ; ArCH,nPr),
2.78 (t, ,J(H,H) = 6.3 Hz, 4 H ; Hl), 2.82-2.91 (m, 8 H ; H3, H8), 5.99 (t.
'J(H,H) = 4.8 Hz, 2 H ; H6), 14.28 (s, 2 H ; NH). 13C NMR (75 MHz, CDCI,):
6 =147.2, 147.0, 144.8. 137.1, 135.6, 132.6, 129.6, 99.0, 34.3, 31.1, 28.6. 26.9,
24.3,23.2,22.9,21.7,13.7. FT-IR(KBr):b[cm-'] = 3178 s(NH).2943 s(CH).
2849 s (CH), 1637 s (C = N). LJVjVlS (CH,CI,): i.,.,[nm](&) = 380 (27000).
296 (19000), 278 (27000). FAB-MS (Xe', 6-8 kV): mjz 535 ( M +1, 100%).
Correct C,H,N-analysis for C34Hd2N6
. (H,O), 5 .
~
4: To a solution of 200 mg (0.37 mmol) of 1 in 300 mL of toluene was added
E
40
20
Li Na K Cs Mg Ca Sr Ba
Fig. 2. Spectroscopic changes observed for solutions of 1 in CH,CI,
M) exposed for one day to metal salts. Extraction efficiency E =
(2.1 x
[R(1) - R(obs)]/[R(I) - R ( l . Mg(NO,),)], where R = A,,ojA,,,. m : CIanion. 0 ' NO; anion.
Ion-selective optical response has also been reported for
the bis(bipyridy1) macrocycle 6, which solubilizes lithium
solchloride in CH,CI, with d e c o l ~ r i z a t i o n .In
~ ~nonpolar
~.
vents this ligand exists in the intramolecularly hydrogen750
bonded form shown in 6, as indicated by the presence of NH
resonances in the 'H NMR spectrum at 6 = 15.0. Although
1,4,5, and 6 all contain lCmembered, fully unsaturated
rings, the presence of cross-conjugated pyridine rings reduces the diamagnetic ring current expected in (4n + 2) annulenes, an effect observed in meta-fused benzannu1enes.l' O1.
Thus, the NH resonances of 1,4, and 6 all appear at relatively low field. It is noteworthy that the macrocyclization Ieading to 1 proceeds in higher yields than that providing 5. The
latter was prepared in 7 % yield by cyclization of the bis(diacetylpyridine) azine and could not be isolated from reaction
of 2,6-diacetylpyridine with 2,6-diacetylpyridine(dihydrazone).[71 As was recently pointed out by Thilgen and
Vogtle," '1 metal-free macrocyclic bis(azines) are rarely reported, apparently because azines are produced under equilibrium control. The yield of the macrocyclization furnishing
1 appears to be influenced partly by precipitation of the
product and partly by kinetic product distribution. Relative
to 2,6-diacetylpyridine, 2 is apparently preorganized for
macrocyclization by the acridine framework. A predetermined conformation can produce unusual and useful effects.
C
VCH Verlagsgesellschafl mbH, W-6940 Weinheim. 1992
170 mg (0.75 mmol) ofDDQ. The reaction mixture was stirred at room temperature under N, for one day and then filtered. The filtered solid was rinsed
thoroughly with toluene, and the filtrates were combined and concentrated
under vdcuum. Recrystallization from toluene gave 125 mg (63 %) of 4 as a
brownish-red solid. M.p. 244-254"C(decomp.). ' H NMR(300 MHz, CDCI,):
6 =l.OO(t,'J(H,H) =6.6Kz,6H;CH3), 1.55(m.8H;CH,CH,CH3).2.03(m,
4 H ; H2), 2.79 (t, 'J(H,H) = 6 Hz, 4 H ; ArCH,nPr), 2.94(m, 8 H; H1, H3), 7.17
(d, ,J(H,H) = 8.4 Hz. 2 H ; H6), 7.30 (m, 2 H ; H7), 7.47 (d, 'J(H,H) =7.8 Hz,
2 H ; HE), 17.61 (s, 2 H ; NH). FT-IR: (KBr): 5 [cm-'1 = 3429 br (NH), 3060 s
(ArH), 2952 s (CH), 2854 s (CH), 1603 s (C = N). FAB-MS (Xe', 6 - 8 KV):
m / z 530 ( M ' , 100%). UV/VIS (CH,Cl,): A,,,[nm] (E) = 266 (33000), 302
(16000), 358 (20000), 374 (22000), 404 (25000). 438 (13000) 464 (18000).
Correct C,H,N-analysis for C,,H,,N,(H,O).
1 . Mg(NO,),: To a mixture of 96 mg (0.37 mmol) of Mg(NO,), . 6 H,O and
50 mL of acetonitrile was added 200 mg (0.37 mmol) of 1. The mixture was
heated at reflux under N, for 15 min. until all of 1 dissolved. The resulting dark
yellow solution was cooled to room temperature and concentrated with a rotary
evaporator. Drying in vacuo gave 277 mg of a dark amber glass. Recrystallization from ethanol gave 85 mg (33%) of a yellow solid. M.p. 170 "C (decomp.).
0570-0833/92/0606-0750S 3 . 5 0 t . 2 5 1 0
Angew,. Chem. Int. Ed. Engl. 31 (1992) N o . 6
'H NMR (600 MHz. CDCI,): [I21 6 = 0.96 (t. 3J(H,H) = 6.9 Hz, 6 H ; CH,),
1.40 (m. 4 H ; CH,CH,CH,), 1.45 (m, 4 H ; CH,CH,CH,), 1.94 (m, 2H ; H7),
2.05 (m, 4H ; H2), 2.26 (m, 4H; H3, H7), 2.63 (m. 4H; ArCH,nPr), 2.79 (ddd,
'J(H,H) =17.2 Hz, '4H.H) = 9.8 Hz, 'J(H.H) = 4.9 Hz, 2H; Hl), 2.94 (m,
IOH; H I , H6, H8), 3.34 (ddd, 'J(H,H) =17.5 Hz, 'J(H,H) = 4.8 Hz,
'J(H,H) = 4.8 Hz, 2H, H3); "C NMR (75 MHz, CDCI,): 6 =159.1, 157.6,
153.0, 144.6, 144.3. 139.1, 136.3, 33.6, 29.8, 28.5, 26.3. 25.2, 25.0, 23.1, 22.4.
20.3,13.6. FT-IR (KBr): [cm-'1 = 3370 br (H,O), 2942 s (CH), 2860 s (CH),
1619m (C = N). FAB-MS (Xe', 6-8 kV): m / i 620 (M-NO,, loo), 557
(M-HN,O,, 21.2%). UVjVIS (CH,CI,): A,,,[nm] ( E ) = 238 (ZSOOO), 296
(16000). Correct C,H,N-analysis for C,,H,,N,O,Mg(H,O), 5 .
Received: December 9, 1991 [Z 5061 IE]
German version: Angew. Chem. 1992, 104, 792
Whereas beginning from A, compounds of the type C are
readily accessible by N, elimination, starting from B (R' =
aryl) the analogous formation of D is not observed."] However, a disilirane D (R' = H) is accessible from the reaction of
CH,N, with tetrakis(2,6-dimethylphenyl)di~ilene,[~]
although
an intermediate could not be observed. Recently we described
a simple, high-yield access to stable phosphanylidensilanes
(phosphasilene~),[~I
so that it is now possible to investigate
the reaction pathways of such compounds with diazoalkanes
and other cycloaddition partners. Herein we report the synthesis and structure of the first azaphosphasiliridine 1 and its
stepwise conversion to the thermolysis products 2-4.
CAS Registry numbers:
1 b, 140926-56-3;2, 140926-54-1;3, 140926-55-2.
[I] T. W. Bell, S. K. Sahni in Inclusion Compounds, Vol. 4, Key Organic Hosr
Systems (Eds.: J L. Atwood, J. E. D. Davies, D. D. MacNicol), Oxford
University Press, Oxford. 1991, p. 325.
(21 T. W. Bell, A. Firestone, R. Ludwig, J. Chem. Soc. Chem. Commun. 1989,
1902; T. W Bell, P. J. Cragg, M. G. B. Drew, A. Firestone, D.-I. A. Kwok.
AngeM,. Chem. 1992,104, 319; Angew. Chem. I n t . Ed. Engl. 1992,31,345;
ibid. 1992, 104, 321 and 1992, 31, 348.
[3] M. F. Marshalkin, L. N . Yakhontov, Zl7. Org. Khim. 1978, 14, 1729; J.
Org. Chem. U S S R (Engl. Trans/.) 1978, 14, 1610.
[4] A. Kumar, E. Chapoteau, B. P. Czech, C. R. Gebauer, M. Z. Chimenti, 0.
Raimondo, Clin. Chern. ( Winsrun-Salem, N C ) 1988, 34, 1709; M. Takagi
in Calion Binding by Macrocycles, (Eds.: Y. Inoue, G. W Gokel), Dekker.
New York. 1990,465; F. Vogtle, M. Bauer, C. Thilgen, P. Knops, Chimia
1991, 45, 319.
[S] T. W. Bell, A. Firestone, J. Am. Chem. SOC.1986, 108, 8109; T. W. Bell,
Y-M. Cho. A. Firestone, K. Healy. J. Liu, R. Ludwig, S. D. Rothenberger,
Org. S w t h . 1990, 69, 226.
[6] V. L. Goedken, Y Park, S.-M. Peng, J. M. Norris, J. A m . Chern. SOC.1974,
96, 7693.
[7] W. Radecka-Paryzek, Inorg. Chim. Acta 1979, 34, 5.
[8] F. De Jong. D. N. Reinhoudt, Stuhilily und Reactivity of Crown Ether
Coniplexa. Academic Press, New York, 1981, 30.
[9] S. Ogawa, R. Narushimd, Y. A m , J. Am. Chem. Soc. 1984, 106, 5760.
[lo] A. T. Balaban, M. Banciu, V. Ciorba, Annulenes. Benio-Hetero-HomoDerivatives und Their Valence Isomers, CRC Press, Boca Raton, FI, USA,
1987, 142-143.
[11] C. Thilgen, F. Vogtle, Chem. Ber. 1991. 121, 671.
[12] The spin systems were identified according to results of a COSY experiment.
B
A
C
D
The reaction of the phosphasilene Is2Si=P-Si(r'Pr)3
(Is = 2,4,6-rF'r3C,H,) with diphenyldiazomethane led to the
[2 + I] cycloadduct lL4]
in 87 % yield, which was isolated in
the form of yellow crystals (Scheme 1). The composition of
Is
\
/si=7
Is
PhZCN,
Si(i Pr),
IS/,,
1s'
\/
,Si(i Pr),
si-p"
N
I
N
1 \CPh,
Is = 2.4.6-iPr3CBH2
J*
Synthesis, Structure, and Thermolysis
of an Unusual Azaphosphasiliridine**
llPC
- N2
By Matthius Driess* and Huns Pritzkow
Dedicated to Professor Friedrich Bickelhuupt
on the occasion of his 60th birthday
The reactivity of disilenes, phosphaalkenes, and diphosphenes towards organoazides and diorganodiazomethanes
leads to new five- and three-membered heterocycles, in which
the bonding is of particular interest."] It was observed that
disilenes can react with organoazides and diazomethanes by a
[2 + 31 or [2 + 11 cycloaddition depending on electronic and
steric factors. In contrast, phosphaalkenes only react by
[3 + 21 cycloaddition, and diphosphenes react with diazoalkanes to give stable diphosphiranes. Of particular interest is
the [2 + I] cycloaddition of disilenes, which for the reaction
with alkylazides and aryldiazomethane derivatives leads to A
and B, respectively; however, for the reaction with alkenes
there are no examples.
[*I Dr. M. Driess. Dr. H. Pritzkow
Anorganisch-chemisches Institut der Universitit
Im Neuenheimer Feld 270, D-W-6900 Heidelberg (FRG)
[**I This work was supported by the Deutsche Forschungsgemeinschaft (SFB
247). We also thank Prof. Dr. W. Siebert (Heidelberg) for his support.
Angew. Chem. Int. Ed. Engl. 31 (1992) No. 6
0 VCH
4
Scheme 1. Synthesis of the heterocycles 1-4.
1 was deduced from the mass spectrum141and a correct elemental analysis. The 31PNMR spectrum shows a singlet at
6 = - 25.6. In the 29Sispectrum a I4N/"N relaxation-broadened doublet is observed for the Si atom in the three-membered ring at extremely high field (6 = - 86.0) and with an
unusually small
coupling constant ( J = 3.9 Hz). In contrast, the corresponding coupling constant for the "Si nucleus
of the Si(Pr), group (99.5 Hz) is very large. In cyclic, threemembered phosphasilanes the 29Sichemical shifts of the ring
atoms lie between 6 = - 31.3 and 6 = -75.3 and show values of 72.5 to 121.7 Hz for the lJp,sicoupling constants.[51
Verlugsgesellschuft mbH, W-6940 Weinheim, 1992
0570-0833/92/0606-0751$3.50+.25/0
751
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