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Optically Active Reference Compounds for Environmental Analysis Obtained by Preparative Enantioselective Gas Chromatography.

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7.3 (m. Pli). 5.6 (s. Cp). 3.62 (m. T H F ) . 1 78 (m. T H F ) . 1.05 (br.s, rBu); 13C NMR
( 2 5 C ) : d =138.6 (d. C,,,. Ph; 'J(P-"C) = 44.3 Hz. 'J(1y5Pt-13C)= 30.2 Hz).
134.X(d.C',.,,,,,.Ph. './(P-"C) = 1 3 . 4 H 7 , 3 5 ( 1 9 ~ P t - 1 3 C
=)25.5 Hz). 129.6(d. C,,,,,z.
Ph. "./(P-'.'C') = 2 H L ) . 128.1 (d, C,,,,. Ph, ' J ( P - 1 3 C )=10.1 Hz), 105.1 ( 5 , Cp),
77.8 (s. CiCH,),). 6X.1 (5. T H F ) . 32.6 (s. C(CH,),). 26 (a. THF): ( - 92 C).
(7 = 136.3 (d. c',!,~,,.
Ph. 'J(P-"C) = 45 Hz). 133.7 (d. C
1 .3 c') = 1.3.4 H r ) . 129.1 (s. Cp0,".Ph). 127.4 (d. C,,.,,,. Ph. 'J(P-"C)
= 9.4 Hz). 104
(s, Cpl. 77 5 (\. C(CH,),). 67.4 (s, T H F ) . 31.4 (7. C(C'H,),). 35.1 i s . T H F ) :
" P I ' H ; NMR (CDCI,. 8 5 % H,PO,, 25 C): 6 = 42.0 (l.l("'Pt. P) = 4577 Hz):
EIMS.iri :(",") =799(47)[Mi + H].535(46)[!4' - PPh,].453(100)[PtPPh3]+.
Received: April 8. 1994
Revised version: June 28. 1994 [Z 6833 IE]
German version: Angrir. C'hc~rir.1994, 106. 2196
[ I ] K. \rasufuku. H. XmiaLaki. Bid//. C'/ri~n1.Soi.J / m . 1972. 45. 2664.
[2] M. C'iriano. J. .A. K. Howard. J. L. Spencer. F. G. A. Stone, H Wadepohl. J
C'/JCWI SOC.I>ri/tot~7h111.s. 1979. 1749.
[ 3 ] H L i n g . M. Herres. L. Zsolnai. W. Imhof, J: Or~nnonwr.C/imm. 1991.40Y. C7.
1993. 12. 5008.
[4] H. Lang. M Herrea. L. Zsolnai. Orgrri~~~n~rrrr//ic.s
[ S ] H. L'ing. L. Zsolnai. J. Orgmroniet C/wm. 1991. 406. C 5 .
[h] H. L,ing. W. Imhof. C l t m Bw. 1992. 125. 1307.
[7] S. 1. Troyanov. V. Varga, K. Mach. Or~unoti~crollic.~
1993. 12. 2820.
[XI J. R R e r e i i p x . L. R. F;ilvello. J Fornies. E. Lalinde. M. Tomis,
Orh.(i~io~ii~,r(i//ii~,\
1993, 12. 6 .
[Y] J. Fornik. M. A . Comer-Saso. E. Lalinde. F. Martinez, M. T. Moreno.
O ~ , ~ ~ I ~ I ~
1992.
I I I11,
J 2873
~ ~ I C ~ ~ / I ~ ~ ~
[lo] Crystal data for 3: C,,H,,O,, ,PPtTi. M , = 833.8, monoclinic. space group
('2,<.. LI = 11.674(4). h = 9.343(2). < = 36.425(7) A.
= 92.23(3) . V =
7370(3) 43.Z = 8 , p ',,, = 1.50 gcm-'. ;.(MoLz)= 0.71073 A. / I = 40.8 cm-',
F(OO0) = 3344. 7 = 293 K. crystal dimensions 0.13 x 0.38 x 0.63 mm. Crystallographic data here collected by Crystallytics Co. (Lincoln, Nebraska) on a
Nicolet (Siemens) Autodiffractometer, 3 < 28 < 46 (01 scan); 5081 independent reflections. 2741 with F > 4u(F) were observed and used for structure
refincmrnt (program system SHELXTL-PLUS I l l ] ) . Cell constants were refined from 31) reflections (including Friedel pairs) with 15 < 20 < 30 . An
;ibsorptioii correction bascd on Y scans was applied. Six standard reflections
were me:isurcd every 300 retlecrions but showed no decay. The structure was
~ o l \ t . db> direct methods and refined on lFol to R = R' = 0.043 Tor 397 variuhles (weighting scheme
= o'(F,)
0.0004F~2),highest shift:error 0.001.
Goodnesi of f i t 1.13. All non-hydrogen atoms, except those of the solvent
molecule were refined anisotropically. All hydrogen atoms were included in
calculated positions and refined as riding atoms (C-H 0.96
and
I ' = 0.1065 .&?). A difference map following convergence showed no peaks
highcr than 1 e k 3 (maximum!minimum difference density 0.76.'
- 1 .I1 C A P ) . Further details of thecrystal structureinvestigation areavailable
on i-equest fi-om the Director of Cambridge Crystallographic Data Centre. 12
Union Road. GB-Cambridge CB2 IEZ ( U K ) . on quoting the full journal citaI
,
I
F
Optically Active Reference Compounds for
Environmental Analysis Obtained by Preparative
Enantioselective Gas Chromatography**
Wilfried A. Konig,* Ingo H. H a r d t , Barbel G e h r c k e ,
Detlev H. H o c h m u t h , Heinrich Hiihnerfuss,
Bernd Pfaffenberger, and G e r h a r d R i m k u s
Dedicated t o Projkssor Hansjijrg Sinn
on the occasion qf'his 65th birthday
The distribution and behavior of toxicologically relevant
xenobiotics in the environment is of increasing scientific interest. Chirdl. biologically active compounds whose enantiomers
produce fundamentally different effects and whose biologiccil
degradation is, as a rule, enantioselective itre of prticular importance in this context. These properties have been observed in
"cyclodiene" insecticides"' and. more recently, in chiral x 1,2,3.4,5,6-hexachlorocyclohexane
(.A-HCH),[21 the enantiomers
of which are selectively accumulated in living organisms. Using
gas chromatography on modified cyclodextrins (CDs). we have
been able to separate a number of polychlorinated hydrocarbons (PCHs) into their enantiomers: heptachlor and cis- and
[runs-chlordane, which were used as insecticides for decades;
their metabolites cis-heptachlor epoxide and oxychlordane;[31
the atropisomeric polychlorinated biphenyls ( P C B S ) ; ~and
~]
bromocy~len[~1
(Fig. 1 ) . Other groups have also used enantiose-
+
A
cis-chlordane
van.-chlordane
oxychlordane
t1011.
[l I ] S H C L . Y T L - P L l ' S Sofruwe Puckuge for I/W Dererniinurioi~of Crj..uu/ Strucr i i r ( ' \ . Release 4.0; Siemens Analytical X-ray Instruments. Inc.. Madison. WI.
USA. 1990.
(121 F. Ozawa. J. W Park, P. B. Mackenzie. P. W. Schaefer, L. M. Henling. R. H.
Gruhhs. J ,4111. C'/im?. Soc 1989. /If. 1319.
[13] M. c'. Bard. P r r ~ Irrorg.
.
Chi!. 1968. 9. 1.
[14] a ) G . Erker. W. FrDmberg, R. Mynott. B. Gabor. C. Kruger. Angov. C/wrn.
1986. 98. 458. A I I ~ C'hcm.
~ . In/. M.Engl. 1986. 25. 463; b) C. Erker, W.
Friimberg. R. Benn. R. Mynott. K. Angermund. C. Kruger, Orgunomrrrr//i~.~
van. - heptachlor epoxide
cis-heptachlor epoxide
heptachlor
1989.,Y.911.
[I51 The t-eaction of 2 (0.216 g. 0.29mmol) and [Cp,Ti(C=CPh)l] (0.11 g.
0.29 iiimol) in T H F gave a mixture ofproducts. The first fraction obtained by
cryst;illi;.atioii l'rom THF!hexane was a yellow solid (0.045 g). The 3 1 PNMR
spectrum indicates this to be a mixture ofcomplexes. The second fraction. an
orange microci-ystalline product (0.1 g, 41 'A yield) was identified by elemental
analysis. inas5 spectrum. and IR and NMR spectra as the previously reported
[C'p2Ti(c'~CPIi),Pt(PPh
,)I [?I.
[I61 H. Lang. D. Seyferth, Z. .tviirurfor.sch. B 1990. 45. 212.
[17] R . A . Head. / I M J I . , ~ .S y i / / i . 1990. 2K. 134.
bromocyclen
a-HCH
Fig. 1. Structural formulae of chiriil xenobiotics
[*I
Prof. Dr. W. A. Konig. Dipl.-Chem. I. H. Hardt. DiplLChem. B. Gehrcke.
Dip[.-Chem. D. H. Hochmuth, Priv.-Doz. Dr.
H. Huhnerfuss. DipLChem. B. Ppdffenberger
lnstitut fur Organische Cheinir der Universitidt
Martin-Luther-King-Platz 6, D-20146 Hamburg ( F R G )
Telefax: Int. code + (40)4123-2893
Dr. G . Rimkus
Lebensmittel- und Veteriniiruntersuchungsamt des Landes
Schles*ig-Holstein, D-24537 Nrumunster
[**I
This research was sponsored by the Deutsche Forschungsgemeinschaft, the
Fonds der Chemischen Industrie. and the Bundesministerium fur Forschung
und Technologie.
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lective gas chromatography in the analysis of PCHs isolated
from different compartments of the environment, and, in several
cases. they have shown that these compounds are metabolized
enantioseIectiveIy.['l
Optically active samples of these compounds have already
been obtained by enantioselective dehydrochlorination, separation of the enantiomers by liquid chromatography (%-HCH['.'I).
and enantioselective synthesis (heptachlor. heptachlor epoxide,
cis- and trun.s-chlordane['. 91); however, enantiomerically pure
(or enriched) reference substances. which can be used in gas
chromatography to determine the sequence of elution of enantiomers, are not commercially available. Using preparative gas
chromatography columns with modified CDs as the chiral stationary phase, we have now succeeded in separating the enantiomers of a selection of PCHs on a milligram scale and with
enantiomeric excesses of between 42 and over 99% (Fig. 2,
Table 1 ) .I1 21
So far, preparative separations on columns packed with CDs
have only been described for the highly volatile inhalation anesthetics enflurane" 31 and i ~ o f l u r a n e , [which
' ~ ~ have separation
factors x > 2 on capillary columns." In the examples reported
here, the separation factors are between 1.02 (e.g.. heptachlor,
trun.r-heptachlor epoxide. bromocyclen) and 1.10 (2-HCH). Al-
Table 1 Isolated yield and enantiomeric excess ((w) obtained in the preparative resolution o l
the enantiomers of chiral xenobiotics by gas chromatography on cyclodextrin (CD) derivatives. I n each case, the racemate (ca. 2 mg) in acetone (ca. 20 m L ) was injected at an injector
temperature of 200 C ; the total weight of sample was ca. 20 mg.
Conipound
( + )-Heptachlor [a]
( - )-Heptachlor
( +)-ci-Heptachlor cpoxide
( - )-cr.\-Heptachlor epoxide [a]
+ I-i,.anv-Hepatachlor epoxide [a]
( - )-rnriic-Heptachlor epoxide
( + )-m-Chlordane [a]
(
( - )-crc-Chlordaiie
( +)-rr.ufwChlordane [a]
( - )rron.\-Chlordaiie
( +)-Oxychlordane
(-)-Oxqchlordane [a]
( + )-Bromocyclen
( - )-Bromocyclen [.I]
( + )-z-HCH [c]
(-)-o-HCH [a]
[ii]
Yield
[mgl
er
2.3
13
1.4
1.1
51.2
65.2
94 6
98.8
h l .0
83.2
50.5
70.5
92.6
9X.3
50.1
3.5
2.0
2.6
1 3
1.5
1. I
2.7
3.5
1.8
1.6
8.7
7.0
CD derivative
['yo1
42.8
53.8
49.3
>99
>99
2.6-di-O-methyl-3-O-pentyl-/~-CD[I01
?.6-di-O-methyl-3-O-pentyl-/~-CD
2.6-di-0-methyl-3-U-pentyl-~-~D
[lo]
2.6-di-O-mcthyl-3-O-pentyl-;.-CD
2.6-di-0-methyl-3-0-pentyl-l(-CD
2,6-di-O-meth~.l-3-O-pentyl-P-CD
?.h-diO-metliyl-3-O-pentyI-/~-CD
2.6-di-O-methyl-3-0-pentyl-/l-CD
2.6-di-0-methyl-3-O-pentyl-/l-CD
2.6-di-0-methyI-3-0-pentyl-/l-CD
6-0-tex-2.3-dimethyl-/~-CD[b] [I I]
h-O-tex-2.3-dimethyl-~~-CD
[b]
h-O-tex-2,3-dimethyl-/~-CD[b]
6-0-tex-2,3-dimethyl-/I-CD [b]
7,6-di-O-methyl-3-O-pentyl-;~-CD
1.6-di-O-methyl-3-O-pentyl-;.-CD
Enantiomer eluted first. [h] t e =
~ dimethylthexylsilql. [c] [r];" = 127.6 ( c = 2. acctone)
though the quantity of sample injected in each individual run
ranged from 2 to 7 mg, satisfactory to very high enantiomeric
purity (with yields of 20-90% for each enantiomer) was obtained by fractionation. In each case, the enantiomers were
characterized by measurement of optical rotation; the order of
elution of the enantiomers can thus be determined for any CD
derivative." 1'
The toxic compounds mentioned above are ubiquitous and
are highly persistent contaminants in the environment; they are
accumulated in the adipose tissue of higher organisms. Sea gull
eggs. liver of roe deer and hare, and different seal organs were
examined; the ratio of enantiomers for the metabolites cis-heptachlor epoxide and oxychlordane deviated significantly from 1.O
in all cases (Table 2). It is not only noticeable that the selectivity
of metabolism differs greatly from one organism to the next, but
also that the (+)-enantiomers are enriched in sea gull eggs and
Table 2. Enmtiomer ratio ( + II-_ determined bq gas chromatography) of ci.\-heptachlor epoxidc and oxychlordane in various samples ot' sea gull eggs. harc liver.
roe-deer liver (from Schlesnig-Holstein). and adipose tissue from seals (from Iceland)
86.1 0
'
9 ee
Sample
A
L
i
0
20
40
tlmin
I
60
0
20
40
tlmin
60
Fig. 2. Determination <if the eniintionieric purity of heptachlor (left) by enantiosclective gas chromatography on a "fused silica" capillary column (25 m ) containing
heplnkis(2.h-di-O-~iefhyl-3-~-pentyl)-~-cyclodextrin
111 polyailoxane OV 1701
(20"/0) at 130 C and of ci\-heptachlor epoxide (right) on a "fused qilica" capillary
column (25 m) containing heptakis(2.6-di-O-inethyl-3-O-pentyl)-~-cyclodextrin
in
polysiloxane OV 1701 (20%) at 160 C; injector temperature 200 C. detector temperature 250 C . carrier gas. hydrogen.
Sea gull egg. 1
Sea gull egg. 2
Sea gull egg. 3
Sea gull egg, 4
Sca gull egg. 5
Hare liver. 1
Hare liver. 2
H x c livei-. 3
Hare I i v x . 4
Hare live[-. 5
Roe-deer liver. I
Roe-deer liver. 2
Roe-deer liver. 3
Roc-deer liver, 4
Roe-deer liver, 5
Scat. 1 ('idipose tissue)
Seal. 2 (adipose tissue)
Seal. 1 (liver)
Seal, 2 (liver)
Seal. I (brain)
Seal. 2 (brain)
< is-Heptachlor epoxide
2.7
1.6
3.3
Osychlordane
2.3
2.1
1.8
15
1.5
1.1
1 5
1 .0
3.7
1.3
2.6
3.2
1
1.3
1 .5
7
6
7
9
0.14
0 18
0.06
0.05
0.11
9
12
14
17
12
0.66
0.54
0.57
0.45
0.57
0.48
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in the liver of roe deer and hare, whereas the (-)-enantiomers
predominate in the adipose tissue of seals. Bromocyclen, which
is used in Europe to counter parasitic infestations of pets and
has been found in fresh water fish, in some cases, in surprisingly
high concentrations of > 1 mg kg- I , is also metabolized enantioselectively."] The ratio of enantiomers (peak area ratio of
(+)-enantiomer/( -)-enantiomer) lies between I .25 and 1.06.
The toxicological implications of these findings are not yet
clear; however. the results show that the enzymatic degradation
of the xenobiotics dicussed here is possible for at least one enantiomer. Degradation of both enantiomers may also be occurring
at different rates. Enantioselective gas chromatography has not
only proven to be a sensitive and selective analytical method for
distinguishing between enzymatic and non-enzymatic degradation of chiral toxic compounds, but can also be used for the
virtually complete preparative-scale resolution of enantiomers
with low separation factors.
The Versatility of the Azido Ligand: Linkage of
Ni" Centers to Form a Chain with One End-toEnd and Three End-On Bridges in Alternation**
Joan Ribas," Montserrat M o n f o r t , Barindra Kumar
Ghosh, and Xavier S o l a n s
In recent years several groups have investigated the correlation between magnetic and structural properties of p-azidonickel(r1) complexes.[', We are now working systematically in
this fieIdl3-'] and have prepared two types of systems whose
structures depend on the amino ligand employed (Scheme 1 ) .
ferromagnetic coupling
antiferromagnetic coupling
N
N
MdN
ReceiLjed: April 2. 1994 [26X191E]
German version: Aiigcw. Cheiii. 1994. 106, 21 75
"I
'N'
N
/
"N\
M
M
\NNN/
N
[I] A. Miyuziki. T. Hotta. S. Marumo, M. Sakai. J. .4gric. F O I JC'hoii.
~
1978. 26.
975 977: A . Miyamki. M. Sakai, S. Marumo. ihid. 1979.27, 1403-1405: i M .
1980. 28. 1310- 1311.
[2] R. Kallenborn. H. Huhnerfuss, W. A. Konig. A i i g w . C'/i[mi. 1991. 103. 328329: .Aiigm. Ciiciii. / i i / . Ed. Eiigi. 1991. 30, 320-321; H. Huhnerfuss. J. Faller.
R K;illenborn. W. A. Konig. P. Ludwig, B. Phffenberger. M. Oehme, G.
Rimkii\. Ciirrulirv 1993. 5, 393-399.
[3] W. A K6nig. D. Icheln. T. Runge, B. Pfaffenherger. P. Ludwig. H . Huhnerfuss.
J H i g h R r , C'hroiiiarogr. 1991. 14. 530-536.
141 W. A KOnig, B. Gehrcke. T. Runge. C. Wolf. .I High Rm. Ciiroiiiorogr. 1993,
16. 376 378.
[5] B. Plhffenbrreer. H. Huhnerfuss. B. Gehrcke. I . H. Hardt. W. A. Kijnig. G.
Riinkui. ('/iciiio\phrre. in press.
[6] H.-R. Bmcr. M. D. Muller. h i d C'1wiii. 1992, 64. 3168 -3175; H.-R. Buser.
M .D Mullei-. C. Rappr h l ' i l ' l J i i . Sci. E3ch~io/.
1992. 26. 1533-1540; H:R.
Busel. M D. Muller. ihid. 1993. 27. 1211 -1220; M. D. Muller. M. Schlabach.
M. Oehnie. ihirl. 1992. 26. 566. S. Mossner. T. R . Spraker. P. R. Becker, K.
Ballschmiter. ~ ' l i i l c r i i o . \ p / i o . c1992. 24. 1171 1180; R. Kallenhorn, M. Oehme.
W Vertcr, H . Parlar. hid. 1994. 28. 89-98,
171 S. .I. C't-istol. J Aiu. C h o i i . .Yo<.1949. 71. 1894.
[XI K . Mollcr. ( ' Bretzke. H . Hiihnerfiiss, R . Kallenhorn. J N.Kinkel. 1. Kopf. G .
Rimku\. . - l i i , y m . Climir. 1994. UM.91 1-912: Aiigru. C/wnr.h i t . Ed. Eiigl. 1994.
33. X 8 1 8x4.
[Y] H. Klmnsycr. W Thieinann. C/ieiiro.s/~/ierE1986. 15. 687 -692.
[lo] W. A . Khnig. B. Grhrcke. D. Icheln. P. Evers, J. Donnecke. W. Wang. J. High
Ri.5 ( ' / i r ( i i i i o / i i ~ q r .1992. I S . 367-372.
[l I ] W A . K6nig. B. Gchrcke. D. H. Hochmuth. C. Mlynek. H. Hopf. T c , / r u / i d v i i
d . \ j i l i i t i . 1994. i. 347- 350.
1121 Steel c.oJ~i~iins
(1m x 5 3 mm) packed with equal proportiona by weight of
cyclodexti-in derivative and polysiloxane OV 1701 ( 2 . 5 % ) o n chromosorh CiH P (I00 120 mesh) were used at temperatures between 110 and 160 C with
helium :is thc'carrier gds at a pressure ofbetween 310 and 600 kPa (corresponds
to a llow, iiirr of 240 and 620 m L m t n - l . respectively): see also 1. H. Hardt. W.
A. Konig. J C%ioirturog.r. ' 4 . 1994, 666. 611-615.
[I31 V Scliui-ip. H . G~-osenick.B. S. Green. Angcii Chcwi 1993. / 0 5 , 1690-16Y1;
Aiig(.ii. C ' / i < ~ i l ~Iiir.
.
Ed. Olgl. 1993. 32, 1662 1663.
[I41 D. U Stacrk. A . Sliitangkoon. G . Vigh. J. Chroiilorogr. A . 1994. 663. 79-85
[I51 J. Meiii~'iild. K. Thompson, D. L. Pearson. W A. Kanig. T. Runge. W.
Franckc. ,S"X~IIW1991. 251. 560 561.
(161 Refercnce siiniplcs can he obtained from Dr. Ehrenstorfer GnibH. B g m S c h l o w - - S t r .ha. D-X6199 Augsburf ( F R G )
~
end-on
end- to-end
Schcme I . Possible coordination modes for azido ligands.
The bridging ligand with its end-to-end (EE) coordination mode
affords antiferromagnetic (AF) d i n ~ c l e a r [ ~and
" ~ one-dimensional (ID) s y s t e ~ n s . [ ~ End-on
~ - ~ ] (EO) coordination is observed in some d i n ~ c l e a r , [ b1
~ +one t e t r a n u c l e a ~ - , [and
~ ~ ~several
one-dimensional polymeric ferromagnetic (F) compounds.[4h1
A new unexDected two-dimensional (2D) complex (Fig. 1 ) with
both EE and EO bridges
has also been characterized['] and displays overall
A F behavior with canting
phenomenon at low temperatures. This variation in
coordination modes. EE
and EO. causes different
magnetic couplings which
appear to be general for the
metal ions C U " , ~Mn",[']
~~
Mn1I1,[81 and Co11,[9]
In continuation of our in$i
vestigations we considered
that the 2 D system presents
Fig. 1 Schematic representation of the
one terminal azido ligand
structurc of the 2D complex [Ni(N,)?on each Ni" atom (Fig. I ) ,
(dmpd)],,
(dmpd = '.'-dimethylpropane-l Jdiamine). showing the differand it should thus be posent kinds of a d o coordination €0.
sible to have three EO
EE, and terminal [ j ] .
bridges. We report here on
the synthesis and characterization of [Ni(N,),(tmeda)],
(tmeda = N,N,N',N'-tetramethylethylenediamine), a novel compound in which the Ni" centers are linked alternately by one EE and three EO bridges to
form a chain (Fig. 2).['01 Each Ni" center completes its distorted
octahedral coordination by binding to one bidentate tmeda lig-
[*I
[**I
Prof. J. Ribas. Dr. M. Monfort, Dr. B. K . Ghosh
Departament de Quimicd Inorganica. Univcrsitat de Barcelona
Diagonal, 647. E-08028-Barcelona (Spain)
Telefax' Int. code + (343) 411-1492
Prof X. Solans
Universitat de Barcelona (Spain)
This work was supported by the Spanish Direccibn General de lnvestigacion
Cieniifica y Tecnica (project PBY1-0241).
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