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Complexes of 1 5-Di(p-tolyl)-1 4-pentaazadien-3-ide Crystal Structures of [Cu(tolylNNNNNtolyl)]3 and [Ni(tolylNNNNNtolyl)2]2.

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atom. Another series of fragments is thereby formed,
whose masses are 78 and 80 amu smaller than those of
bromine-containing peptide fragments (Fig. 3).
3 4
I ,5-diaryl-3-methylpentaazadienes with compounds of molybdenum in various oxidation states. Cleavage of the N5
chain always takes place in such reactions. In the reaction
with MoCI, we obtained arenediazonium hexachloromolybdate(v) as major product.
Unsubstituted 1,5-diarylpentaazadienes 1 have acidic
character in position 3. Consequently, in aqueous ammonia, the pentaazadienide ion 2 is readily formed. From
such solutions, the corresponding 1,5-diarylpentaazadienido complexes can be precipitated by addition of amminemetal complexes. Up to now we have only been able to
obtain complexes with monovalent ions of TI, Cu, and Ag,
Fig. 3. FAB spectrum of positive ions of Bdbs-Val-Ala-Ala-Phe;m / z 668=[MH]+, m / z 690=[MNa]+. Bromine-free fragments: m / z 120. 255, 354, 425, 590.
The interpretation is more difficult for peptides whose
amino acids contain side-chain functional groups. In each
case studied, however, we obtained more informative spectra from the derivatized than from the free peptides.
Received: January 14, 1985:
revised: February 4, 1985 [Z 1133 IE]
German version: Angew. Chem. 97 (1985) 408
CAS Registry numbers:
Val-Ala-Ala-Phe, 2 1957-32-4; Dns-Val-Ala-Ala-Phe, 96095-87-3; Bdbs-ValAla-Ala-Phe, 96095-86-2.
[I] M. Barber, R. S. Bordoli, R. D. Sedgwick, A. N. Tyler, J . Chem. SOC.
Chem. Commun. 1981. 325.
[2] D. H. Williams, C. V. Bradley, S. Santikarn, G. Bojesen, Eiochem. J . 201
(1982) 105.
[3] M. E. Rose, M. C. Prescott, A. H. Wilby, 1. J. Galbin, Biomed. Mass Specfrom. I / (1984) 10.
[4] K. B. Tomer, F. W. Crow, M. L. Gross, K. D. Kopple, Anal. Chem. 56
(1984) 880.
(51 Experimental procedure for the derivatization with Dns-CI or Bdbs-CI:
The peptide ( 1 p o l ) is dissolved in 0.2 M NaHCO, (60 KL). After addition of a 50mM solution of Dns-CI o r Bdbs-CI in acetone (mole ratio peptide :reagent= I :3), the mixture is incubated for 1.5 h at 40°C. Subsequently, the acetone is distilled off and the products acidified with 10?h
H3P01. The derivatized peptide is isolated by RP-HPLC. Fractions are
collected at frequent intervals, combined, and freeze dried. The residue is
dissolved in a small amount of methanol for the FAB mass spectrometric
[6] Finnigan MAT 8500 mass spectrometer with modified ion source for
FAB-MS; xenon canon (ION TECH LTD., Teddington, U.K.); matrix
material: glycerin; the glycerin background was subtracted from the FAB
[7] S. K. Sethi, C. C. Nelson, J. A. McCloskey, Anal. Chem. 56 (1984) 1977.
Complexes of 1,5-Di(p-tolyl)-l,4-pentaazadien-3-ide,
Crystal Structures of [Cu(tolylNNNNNtolyl)13 and
By Johannes Beck and Joachim Strahle*
Suitably substituted 1,4-pentaazadienes are stable at
room temperature.",'] We have studied the reactions of
[*] Prof. Dr J . Strahle, Dipl.-Chem. J. Beck
lnstitut fur Anorganische Chemie der Universitftt
Auf der Morgenstelle 18, D-7400 Tubingen 1 (FRG)
[**I This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie.
Angew. Chew!. Int. Ed. Engl. 24 (1985) No. 5
divalent ions of Mn, Ni, Zn, Cd, Pd, and Cu, and trivalent
cobalt. The structures of 3, 4, and 5 have been determined.',]
The dimeric bis( 1,5-ditolyl-1,4-pentaazadien-3-ido)nickel(ii), 3, is formed in the form of a brown, crystalline
powder from ammoniacal solution.'41It is paramagnetic; at
room temperature, p =3.1 B.M., corresponding to two unpaired electrons per metal ion. The complex decomposes
at 120°C. From a tetrahydrofuran (THF)/n-hexane mixture, monoclinic single crystals of the composition 3 ' T H F
crystallize out. Crystallization of a triclinic and a tetragonal modification was also observed. The structure analys ~ s [(Fig.
~ ] I ) shows that in 3 four N5 zig-zag chains, whose
longitudinal axes run parallel, each coordinate two Ni'+
[Ni(p-tolyl-NNNNN-p-tolyl),l, [Cub-tolyl-NNNNN-p-tolyl)l,
ions in a distorted octahedral fashion. The atoms N1, N3
and N5 of each N,-chain participate in the coordination.
The base of the octahedron is formed by two chelate-likebonded N,-fragments. The mean N-Ni-N angle of 59.3"
in the chelate ring is relatively small, while the neighboring
angles of 117-125" in the base of the octahedron are
greater than the ideal value. The Ni-N distances within
the base are 213 pm. The distances to the apices of the octahedron are somewhat shorter (207 pm). The Ni-N distances indicate single bonding, as is also found in amminenickel c o m p l e ~ e s [ ~ and
, ' ~ in dimeric bis( 1,3-diphenyltriazenenickel(i~).~~~
Reaction of an ammoniacal solution of 1,5-ditolylpentaazadiene with tetraamminecopper(i1) ions initially leads
to formation of a brown precipitate of 6.This CU(II)compound is readily soluble in almost all organic solvents. Independently of the solvent employed, evolution of nitrogen and reduction to 4 takes place on heating. The
color of the solution turns deep-red. From THF/n-hexane,
0 VCH Verlugsgesellschuft mbH. 0-6940 Weinheim 1985
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plained in terms of bonding interactions. In the case of the
Cu:+ unit, a dsp' hybridization of the C u atoms is conceivable, such that two Cu-Cu bonds can be formed, with
each of the outer Cu atoms still having an unpaired electron. The observed magnetic properties are consistent with
this model if an antiferromagnetic coupling is assumed.
The terminal atoms Cul and Cu3 are each bent out from
the planes of the three coordinating N atoms by about
18 pm, thus indicating repulsion between the Cu atoms.
In the dimeric TI' complex 5,I'I two TI ions are coordinated trigonal-pyramidally by two N,-chains, resulting, as
in 3, in an alternating chelate-like and monodentate bonding of the metal ions.
The interatomic distances in the planar N5 chains of all
the complexes so far investigated are consistent with partial delocalization of the n-electrons. The shorter N1-N2
and N4-N5 distances of about 128 pm are slightly longer
than a N N double bond, while the longer N2-N3 and
N3-N4 bonds are markedly shorter than the value normally found for a N N covalent single bond."']
Fig. I. Structure of 3 in the crystal. Important bond lengths [pm] and angles
Ni-N 205.2(3) to 214.0(3), NI-N2 127.2(4) to 128.2(4), N2-N3 133.8(4)
to 135.8(4), N3-N4 134.2(4) to 138.7(4), N4-NS 126.9(4) to 129.3(4),
Nil-Ni2 331.0(1): N-N-N 104.4(3) to 113.5(3). The first of the two figures
alongside the N atoms refers to the chain, the second, the only figure given in
the text, refers to the number of the N atom in the chain.
monoclinic 4 ' T H F . 0.5 C6H1419]crystallizes in the form of
red pseudohexagonal platelets. The complex is air-stable,
and, unlike 3 . THF, it decomposes explosively on heating
to 160°C. Associated with its weak paramagnetism, the
magnetic moment increases between 113 and 303 K from
~ ~ 0 . to
3 0.52
B.M. per C u + ion.
In 4"01 (Fig. 2), three N5 zig-zag chains coordinate three
linearly arranged C u + ions with N1, N3, and N5, such that
each metal atom is in a trigonal-planar environment. The
Cu-N distances to the outer N1 and N5 atoms, with a
mean value of 203.6 pm, are somewhat longer than the distances to the more strongly basic atoms N3 (mean distance
Cu2-N3: 194.5 pm). They largely correspond to the sums
of the covalent radii (202 prn["]), and to the CU-N distances in tetrameric (1,3-dimethyltriazene)copper( I)"'] and
dimeric (1,3-diphenyltriazene)copper(1).~~~~
The Cu-Cu
distances of 234.8 and 235.8 pm in the linear Cu:+ chain
of 4 are the shortest values found so far in C u i complexes.
Comparable Cu-Cu distances of about 242 to 246 pm are
found, for example, in alkyl-"41 and arylcopper(1) compounds"'' or in the iodocuprate C U ~ I ; . " ~ It
' is still not
fully clear whether such short Cu-Cu distances can be ex-
Fig. 2. Structure of 4 in the crystal. Important bond lengths [pm] and angles
['I: CuI-NI 200.6(5) to 205.2(6), Cu2-N3 194.1(5) to 195.2(6), Cu3-N5
202.7(5) to 205.0(5), Cul-Cu-7 234.8(2), Cu2-Cu3 235.8(2), NI-N2 126.7(6)
to 127.2(7), N2-N3 132.4(7) to 135.4(7), N3-N4 132.0(6) to 134.2(7),
N4-NS 127.1(6) t o 129.6(6), Cul-Cu2-Cu3
180.00(1), NI-Cul-NI
114.0(2) to 123.1(2), N3-Cu2-N3
116.6(2) to 121.7(2), NS-Cu3-N5
114.7(2) to 122.4(2), N-N-N 109.7(6) to l13.9(6). The first of the two figures
alongside the N atoms refers to the respective chain, the second, the only figure given in the text, refers to the number of the N atom in the chain.
41 0
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Received: January 10, 1985;
revised: January 28, 1985 [Z I128 IE]
German version: Angew'. Chem. 97 (1985) 419
CAS Registry numbers:
3, 96129-15.6; 4, 96129-17-8; [Ni(NHz)J2+, 15365-74-9: [Cu(NHT)$',
[ I ] H. von Pechmann, L. Frobenius. Chem. Ber. 27 (1894) 899.
[2] C. Suling in: Houben- Weyl, Methoden der organisrhen Chemie. Ed. X / 3 ,
Thieme, Stuttgart 1965, p. 695.
131 Structure of 5 : J. Beck, J. Strlhle, Z . Narurforrch.. to be published.
[4] Procedure: To a saturated solution of 1,5-di-p-tolyl- 1,4-pentaazadiene
(0.2 g, 0.79 mmol) in concentrated aqueous ammonia was added a slight
excess of [Ni(NH,),]'+ (likewise in concentrated ammonia). Over a period of several hours, a light brown precipitate of 2 separated out. This
was filtered off and washed with water to remove the excess ammonia.
The precipitate was then dried over P20, in vacuo. Yield quantitative.
151 3 . T H F : P2,/n, a = 1180.0(2), b=2898.7(6), c = 1801.1(5) pm,
[~=91.71(1)", Z = 4 , R=0.075 for 6788 independent reflections with
I > 3 o ( l ) (Enraf-Nonius CAD4, CuK,,); see also [lo].
161 T. Iwamoto, T. Miyoshi, Y. Sasaki, Acta Crvsfallogr. B30 (1974) 292.
[7] B. N. Figgis, P. A. Reynolds, A. H. White, G. A. Williams, S. Wright, J.
Chem. Soc. Dalton Trans. 1981, 997.
[S] M. Corbett, B. F. Hoskins, N. J. McLeod, B. P. O'Day, Aust. J . Chem. 28
(1975) 2377.
191 Procedure: To a saturated solution of 1,5-di-p-tolyl-1,4-pentaazadiene
concentrated aqueous ammonia was added an excess of [Cu(NH3)J2+
(likewise in concentrated ammonia). A brown, crystalline precipitate of
6 separated out immediately. Addition of [ C U ( N H , ) ~ ] ~was
+ continued
until the supernatant liquor was intense green and no further precipitate
separated. The precipitate was filtered off and washed with water to remove the excess ammonia. The precipitate was then dried over P 2 0 i in
vacuo. Reduction to 4 was accomplished by heating in THF: the brown
Cu(ii)-compound was dissolved in a little T H F under N2 and the resulting solution heated to boiling. Vigorous evolution of gas was observed
and the color of the solution changed from brown to intense red. Treatment of the solution with n-hexane led to precipitation of deep-red crystals of 4.THF.0.5C+,H,4.
[lo] 4 : P2,/c, a=1477.3(1), b= 1478.7(4), c=2284.5(2) pm, /3=91.06(1)",
R =0.064 for 2569 independent reflections with I > 3o(I) (Enraf-Nonius
CAD$ Cu,,,).
Further details of the crystal structure investigations are
available on request from the Fachinformationszentrum Energie Physik
Mathematik, D-7514 Eggenstein-Leopoldshafen 2, on quoting the depository number CSD 51 225, the names of the authors, and the full citation of the journal.
[ I I] L. Pauling: ?he Nature of the Chemical Bond and the Srructure of Molecules and Cryrals. Cornell University Press 1960: Die Nalur der chemischen Bindung. Verlag Chemie, Weinheim 1968.
1121 J . E. OConnor, G. A. Janusonis, E. R. Corey, J. Chem. Soc. Chem. Commun. 1968. 445.
1131 1. D. Brown, J. D. Dunitz, Acta Crystallogr. 14 (1961) 480.
1141 J. A. J. Jarvis, B. T. Kilbourn, R. Pearce, M. F. Lappert, J. Chem. Soc.
Chem. Commun. 1973, 475.
[IS] S. Gambarotta, C. Floriani, A. Chiesi-Villa, C. Guastini, J . Chem. Soc.
Chem. Commun. 1983, 1156.
[I61 H. H a d , F. Mahdjour-Hassan-Abadi, Z. Naturforsch. 8 3 9 (1984) 149.
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Anyew. Chem. l n l . Ed. Engl. 24 17985) No. S
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crystals, structure, ide, complexes, tolylnnnnntolyl, pentaazadien, tolyl
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