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Synthesis and spectral characteristics of 4,4'-dimethoxythiobenzophenone
SHORT COMhIUSIChTIONS
488 Synthesis
and spectral
characteristics benrophenone
of 4,4’-dimethoxythiw
The reaction of clcment;Ll sulfur with N-(4,4’-dimethoxybenzol~ydrilidenc)benzylamine, (CH~OC~M~)~C=NCI~~,C,IH~,, Schonbcrg’s rcqent, was reported by Sc~osuer~ of elemental AND Cil)’ ORY, \\‘Arerg’s reagent rrncl sulfur is somewhat less straightforward tlian was first sul~l~os~d by OI*Y. Howcvcr, the tlctcrminution may be standardized and cnrricd out under coxltrollcd conditions to give s;ltisfactory analytical results for sulfur. ‘J’hc l&My colc~rc~cltlliokctone is easily determined photomctricnlly.
-___.__
_
__-___
__..
.-.
. . .._.__.. _..
_
_
Stlw~ll! ---
.._... --
1’rCSCllt
work n GA~T~TIZI~MAN” kiCIIONll151~C;’
r~osAcll” ‘Tlicorcticirl
-
7tr.p. &,
fio.53
PG ____..--_-
5.4
ci9,70 7”. I I) -
5.01 0.03 -
6’&7,1
5.10
&J
1’2,33 IJ.gCi 1’2.39
AI _ ___.. .-_. 11.10
12.39 12.13 12..) I
_....
__._.
(“) .._.
110-I
._
17
115 11.)-l 15
I16 -
Spectroscopically pure tliiolcctone was required for its satisfactory characterization. The synthesis and purification proccclures reported below proved to be particularly convenient because they minimized 11;~~~dlin~proI~lcms due to light sensitivity, air oxidation, and tlicrrnal instability of the product. The purity of the thiokctonc clcscril~cd llcrc seems the highest yet attainccl, and tlzc compound annlysis (Table I) is tllc most complete yet reported. The infrared spectrum shown in Fig. x is previously unreported. Of particulnr interest arc two absorption bands which arc newly assigned to carbon-sulfur bonding in the thioketone, This communication also corrects the assignment of the 773 cm-’ band, erroneously attributed by WILI.IA;\IS~ to N-I-I bending. The frequency so assigned should have been 750 cm-1 whcrcas 773 cm-1 is a methyl band. Extinction cosfficients and absorption maxima in the visible range (Table II) for the thiokctone are given for two new solvents ancl for nnothcr solvent whcrc our results were not in agreement with the work of previous investigators. The synthesis is similar to that of I~OSACH AXI) GUIILOUZO~ with improvements in yield attributable to the utilization of a single solvent at a lower temperature.
SHORT
3.5
4
!I .
COMMUNICATIONS
Cl
489 Microns
7
9
I
11
1
IS
I
I200
Wavenumber
1000
.
cm-l
I:$. I. tnfrwcd spcctrutn of .),.+‘-dill~ctllos~~~li~~t~~n~~t~t~~n~n~ (Beckman IIt-7. with KISr disk). Comparison of ttw spectra of .),.)‘-tlit~~ctt~ox~tt~iol~cr~zoI~tic~~onc (I), 4,.~‘-cli:i~c~t~ox~~~n~oI~t~~nonc (If), ant1 t~is(~-ri~cttiox~pti~n~l)-~~~~lt~~t~;~i~~~in~ (II I) shcws 3 txmtls in I which arc not in It or III: I 221 cm-l. 10.15 cm-l, nntl 7.10 cm-*. Ttw first L arc’ strong lxu~rls, and ttw last is weak. ;ulct niadc the assipnnicnt Othcrs~~~ IliLVC rcportctl ttlc t 22 I cl11 - ’ l>;lrld at 1rr.t and I.219 cmThis study seems to verify that nssignrncnt ant1 to indicate that the to carbon-sulfur bonding. 1045 cm - * arid 7.p cm-* l~nritls arc ;itso ossociatccl with c;wbon--sulfur bonding iii arornirtic thiokctoncs.
‘l’hBI.15
_.--._.-
- __.
-
^.
. . _ ._
.-
.S0h?t1l
_ _,__ __
____ __ _______.__
. .._ ___ ._.
tlisutficlc Cyctotiexanc PI-l+oI~anol u-l?x~I~not Ethiulol Ethanol
I:‘
_. . _
._ (A
. .._ 6s.
-.
Cnrbon
__.___ ____._. l
The
_ ..__.--.__.- .._... -_--.-
I3cckmnn
9mdc
II
._. _- _.._..
- 1l.W
..__..
- 1)
__ _,_...
-
.._
2130 3’5 344 3’4 277 278
--
ir.mur
_....
593 500 577 56s 57” 577
-...
.
----..
---
_.---..--.
-...-
.-.-
ItrJ>remc
-..
______.
-
lDrcseut work I+cscnt work l%wcnt work 10 11 12
-....-- - _.__.-. _.._..._.. _..- .-.--..- .^-._-.-_. -_- ______._ -__
IDIS sI,cctrot)tlotonlctcr
was cntit~ratctl
usinK ttlc 540 mercury
tint.
Experimental The4,4’-dimethoxythiobenzopllenone was prepared by rcfluxing 14.35 g (5.75 * 10-2 moles) of 4,4’-dimetl~oxybenzophcnone with excess phosphorus pcntasulfide in 250 ml of reagent-grade carbon tetrachloridc for 30 h. ‘The solution was decanted, washed 3 times with zso-ml portions of saturated aqueous sodium carbonate followed by 3 qjo-ml distilled water washes, and dried over anhydrous sodium carbonate. The carbon tctrachloride solution was clrromatngrapl~cd through an activated alurnina column previously washed with carbon tetrachloricle. Unrcactecl ketone was retained while thioketonc was eluted. Center cuts of the thiokctone fraction from several chromatograms were collected unclcr nitrogen and storecl in the Clark. The solvent was evaporated at reduced pressure, and 6.0 g (2.3 - IO-” moles) of crystalline 4,4’dimethoxythiobenzophcnone was obtained and stored under nitrogen in an arnbcr glass bottle. Yield through all operations was 40%. A r~nl.Chirta. A cla, 31 (xgG4) 488-490
SHOIW
490
COhlMU~;ICATIOXS
The very strong rG43 cm-1 carbonyl band of the ketone was absent in the spectrum of the thioketonc. The melting point of the product, dctcrmined in a scaled capillary under one atmosphere of nitrogen (30”), was xx&-117~. Lle~arttitent of Chentistvy, Lo~hiann State University, Baton Ihuge, Ln. (U.S.A.)
The
direct
polarographic determination in nitric acid media
H. 33. WILLIAMS 1;. M. HII_RURS* I<. YAItlXtOUGH
of uranium(W)
Exccllcnt polarographic waves for the uranium(V1) to (V) step c:in be obtained in strongly acidic media, such as sulfuric, hydrochloric and pcrchloricL-3. I’IcoI~s-r~l has of uranium(V1) in nit&c acid and dcscribcd conclitions for the “in-line” dctcrmination cliscussccl the cffcct of tri-qbbutyl phosphate (‘1’131-‘) ant1 iron( III) on the uranium wave. Generally, when uranium is cletermincd in the prcscncc of corrosion and fission products, uranium is first separatcdG before its polarographic dctcrmination in a nonaqueous medium. The present paper describes a rapid method for the direct polaroelcctrolytc graphic detcrminntion of uranium in synthetic solutions. ‘The supporting is nitric acicl saturated with a THl’-odorless kcrosenc mixture Potcntinl interfcrcnccs and methods for their climinatiorl are outlinccl. .
A “Mctrohm Polarccord E 2x6 12” was used to rccorcl the polarograms. A 25-ml “Mctrohm” cell with 5 ground sockets and proviclcd with a convcntionil! dropping mercury cathode and a saturatccl calomcl clcctroclc (S.C.E.) was cmployccl. The capillary had the following chnmctcristics: .I)c E 2.2501 mg/scc and t x 3.11 set in 1.G N nitric acid at an applied potcntinl of 0.35 V vs. S.C.E
488 Synthesis
and spectral
characteristics benrophenone
of 4,4’-dimethoxythiw
The reaction of clcment;Ll sulfur with N-(4,4’-dimethoxybenzol~ydrilidenc)benzylamine, (CH~OC~M~)~C=NCI~~,C,IH~,, Schonbcrg’s rcqent, was reported by Sc~osuer~ of elemental AND Cil
-___.__
_
__-___
__..
.-.
. . .._.__.. _..
_
_
Stlw~ll! ---
.._... --
1’rCSCllt
work n GA~T~TIZI~MAN” kiCIIONll151~C;’
r~osAcll” ‘Tlicorcticirl
-
7tr.p. &,
fio.53
PG ____..--_-
5.4
ci9,70 7”. I I) -
5.01 0.03 -
6’&7,1
5.10
&J
1’2,33 IJ.gCi 1’2.39
AI _ ___.. .-_. 11.10
12.39 12.13 12..) I
_....
__._.
(“) .._.
110-I
._
17
115 11.)-l 15
I16 -
Spectroscopically pure tliiolcctone was required for its satisfactory characterization. The synthesis and purification proccclures reported below proved to be particularly convenient because they minimized 11;~~~dlin~proI~lcms due to light sensitivity, air oxidation, and tlicrrnal instability of the product. The purity of the thiokctonc clcscril~cd llcrc seems the highest yet attainccl, and tlzc compound annlysis (Table I) is tllc most complete yet reported. The infrared spectrum shown in Fig. x is previously unreported. Of particulnr interest arc two absorption bands which arc newly assigned to carbon-sulfur bonding in the thioketone, This communication also corrects the assignment of the 773 cm-’ band, erroneously attributed by WILI.IA;\IS~ to N-I-I bending. The frequency so assigned should have been 750 cm-1 whcrcas 773 cm-1 is a methyl band. Extinction cosfficients and absorption maxima in the visible range (Table II) for the thiokctone are given for two new solvents ancl for nnothcr solvent whcrc our results were not in agreement with the work of previous investigators. The synthesis is similar to that of I~OSACH AXI) GUIILOUZO~ with improvements in yield attributable to the utilization of a single solvent at a lower temperature.
SHORT
3.5
4
!I .
COMMUNICATIONS
Cl
489 Microns
7
9
I
11
1
IS
I
I200
Wavenumber
1000
.
cm-l
I:$. I. tnfrwcd spcctrutn of .),.+‘-dill~ctllos~~~li~~t~~n~~t~t~~n~n~ (Beckman IIt-7. with KISr disk). Comparison of ttw spectra of .),.)‘-tlit~~ctt~ox~tt~iol~cr~zoI~tic~~onc (I), 4,.~‘-cli:i~c~t~ox~~~n~oI~t~~nonc (If), ant1 t~is(~-ri~cttiox~pti~n~l)-~~~~lt~~t~;~i~~~in~ (II I) shcws 3 txmtls in I which arc not in It or III: I 221 cm-l. 10.15 cm-l, nntl 7.10 cm-*. Ttw first L arc’ strong lxu~rls, and ttw last is weak. ;ulct niadc the assipnnicnt Othcrs~~~ IliLVC rcportctl ttlc t 22 I cl11 - ’ l>;lrld at 1rr.t and I.219 cmThis study seems to verify that nssignrncnt ant1 to indicate that the to carbon-sulfur bonding. 1045 cm - * arid 7.p cm-* l~nritls arc ;itso ossociatccl with c;wbon--sulfur bonding iii arornirtic thiokctoncs.
‘l’hBI.15
_.--._.-
- __.
-
^.
. . _ ._
.-
.S0h?t1l
_ _,__ __
____ __ _______.__
. .._ ___ ._.
tlisutficlc Cyctotiexanc PI-l+oI~anol u-l?x~I~not Ethiulol Ethanol
I:‘
_. . _
._ (A
. .._ 6s.
-.
Cnrbon
__.___ ____._. l
The
_ ..__.--.__.- .._... -_--.-
I3cckmnn
9mdc
II
._. _- _.._..
- 1l.W
..__..
- 1)
__ _,_...
-
.._
2130 3’5 344 3’4 277 278
--
ir.mur
_....
593 500 577 56s 57” 577
-...
.
----..
---
_.---..--.
-...-
.-.-
ItrJ>remc
-..
______.
-
lDrcseut work I+cscnt work l%wcnt work 10 11 12
-....-- - _.__.-. _.._..._.. _..- .-.--..- .^-._-.-_. -_- ______._ -__
IDIS sI,cctrot)tlotonlctcr
was cntit~ratctl
usinK ttlc 540 mercury
tint.
Experimental The4,4’-dimethoxythiobenzopllenone was prepared by rcfluxing 14.35 g (5.75 * 10-2 moles) of 4,4’-dimetl~oxybenzophcnone with excess phosphorus pcntasulfide in 250 ml of reagent-grade carbon tetrachloridc for 30 h. ‘The solution was decanted, washed 3 times with zso-ml portions of saturated aqueous sodium carbonate followed by 3 qjo-ml distilled water washes, and dried over anhydrous sodium carbonate. The carbon tctrachloride solution was clrromatngrapl~cd through an activated alurnina column previously washed with carbon tetrachloricle. Unrcactecl ketone was retained while thioketonc was eluted. Center cuts of the thiokctone fraction from several chromatograms were collected unclcr nitrogen and storecl in the Clark. The solvent was evaporated at reduced pressure, and 6.0 g (2.3 - IO-” moles) of crystalline 4,4’dimethoxythiobenzophcnone was obtained and stored under nitrogen in an arnbcr glass bottle. Yield through all operations was 40%. A r~nl.Chirta. A cla, 31 (xgG4) 488-490
SHOIW
490
COhlMU~;ICATIOXS
The very strong rG43 cm-1 carbonyl band of the ketone was absent in the spectrum of the thioketonc. The melting point of the product, dctcrmined in a scaled capillary under one atmosphere of nitrogen (30”), was xx&-117~. Lle~arttitent of Chentistvy, Lo~hiann State University, Baton Ihuge, Ln. (U.S.A.)
The
direct
polarographic determination in nitric acid media
H. 33. WILLIAMS 1;. M. HII_RURS* I<. YAItlXtOUGH
of uranium(W)
Exccllcnt polarographic waves for the uranium(V1) to (V) step c:in be obtained in strongly acidic media, such as sulfuric, hydrochloric and pcrchloricL-3. I’IcoI~s-r~l has of uranium(V1) in nit&c acid and dcscribcd conclitions for the “in-line” dctcrmination cliscussccl the cffcct of tri-qbbutyl phosphate (‘1’131-‘) ant1 iron( III) on the uranium wave. Generally, when uranium is cletermincd in the prcscncc of corrosion and fission products, uranium is first separatcdG before its polarographic dctcrmination in a nonaqueous medium. The present paper describes a rapid method for the direct polaroelcctrolytc graphic detcrminntion of uranium in synthetic solutions. ‘The supporting is nitric acicl saturated with a THl’-odorless kcrosenc mixture Potcntinl interfcrcnccs and methods for their climinatiorl are outlinccl. .
A “Mctrohm Polarccord E 2x6 12” was used to rccorcl the polarograms. A 25-ml “Mctrohm” cell with 5 ground sockets and proviclcd with a convcntionil! dropping mercury cathode and a saturatccl calomcl clcctroclc (S.C.E.) was cmployccl. The capillary had the following chnmctcristics: .I)c E 2.2501 mg/scc and t x 3.11 set in 1.G N nitric acid at an applied potcntinl of 0.35 V vs. S.C.E