The diynamines 4a-k are thermally stable, mainly crys- talline compounds, which are unaffected by storage. The constitution of the diynamines 4, which with the exception of 4diZ1 are novel compounds, was verified by exact ele- mental analyses and spectroscopic data: The very intense IR absorptions in the 2188-2228 cm- ' region (often ac- companied by bands of medium to low intensity at 2065 - 2153 cm-I), the appearance of the molecular ion in the mass spectra, and of the signals of the four acetylenic C atoms in the sample I3C-NMR spectra of 4c and 4i are characteristic. The reactivity of (1,3-diynyl)amines is, with the exception of some hydr~lyses["~, unknown; the addi- tions and cycloadditions of electrophilic molecules which we have studied up till now appear to proceed preferen- tially at the C C triple bond adjacent to the amino group. In contrast, reaction of the stannylated diynamine 4g with chlorodiphenylarsane afforded the novel diynamine 4j (R3 = AsPh2) via exchange of the stannyl group.

Received: September 2, 1981, in revised form: February I , 1982 [Z 35 IEj

German version: Angew. Chem. 92 (1982) 289 The complete manuscript of this communication appears in:

Angew. Chem. Suppl. 1982, 122-729

121 J. L. Dumont, W. Chodkiewicz, P. Cadiot, Bull. SOC. Chim. Fr. 1967,

[4j B. P. Gusev, L. A. Tsurgozen, V. F. Kucherov, Izv. Akad. Nauk SSSR.

[7] A. Roedig, M. Four&, Chem. Ber. 109 (1976) 2159.

1197.

Ser. Khim. 1972, 1098.

Novel Pseudooxocarbon Dianions of the C4 Series** By Gunther Seitz*, Rudianto Sutrisno, Bernd Gerecht, Guido Offermann, Roland Schmidt, and Werner Massa

Exchange of the oxygen atoms in oxocarbon dianions 1 by substituents X = S , NR, or =C(CN)2 leads to pseu- dooxocarbon dianions 2 having similarly delocalized n- electron systems[']. We have now found that by analogy to the hydrazinolysis of the thiooxocarbon dianion 3 of the C4 series to give the tetraaza[4]radialene 4l3], the highly reactive squaric acid derivatives 5 and 6 permit a com- plete exchange of substituents in only one step with C- or N-nucleophiles. Thereby, novel pseudooxocarbon dian- ions of the C4 series such as 7a and 7b are formed with malondinitrile and a base, and the first isolable, air-stable salt of the iminocarbon dianion 10[9a.b1 is formed in excel- lent yield using cyanamide.

The spectroscopic data confirm the high symmetry of these novel aromatic dianions: 7a: I3C-NMR ([D,]DMsO): 6= 149.6 (four-ring c ) , 117.6 (CN), 39.7 (C-CN), 34.4 (NCH3); IR (KBr): 2200 (CN), 1440 cm- ' (four-membered ring); UV (H20): 1,,,=484 nm (Ig~=4.69).- 10: I3C-NMR ([D,]DMSO): 6 = 173.2 (four- membered ring C), 117.5 (CN); IR (KBr): 2178 (CN), 1510 cm- ' ; UV (H,O): ;1,,,=376 nm (Ig&=4.6).

A high charge-density on the exocyclic methylene car- bon atoms of 7a is evident from their I3C-NMR shift,

I*] Prof. Dr. G. Seitz, Dr. R. Sutrisno, B. Gerecht, G. Offermann Pharmazeutisch-chemisches Institut der Universitat Marbacher Weg 6, D-3550 Marburg (Germany) Dr. W. Massa, R. Schmidt Fachbereich Chemie der Universitat Hans-Meerwein-Strasse, D-3550 Marburg (Germany)

the Fonds der Chemischen Industrie. [**I This work was supported by the Deutsche Forschungsgemeinschaft and

1 2

4NH2-NH2 H2N-\ /pNH2 H 2 N - N & W 2

3 4

NC CN120 Nt-C,, ,C-CN ""Xs 4CH2(CN12,

Pyridine (CH32N Nc-( , -CN

6

7b,X0=No8

NnO - Bu

CN NC-N, N-cN]~"

4H2N-CN NaO - Bu

N C - i -CN 6 10 9 CN

which is comparable to that of the dianion 9['] at 6=38.0; the extreme value of 6=24.8 for the next lower homologue of 7, the pseudooxocarbon dianion Sf8I is, understandably, not reached.

The X-ray structure analysis of 7a indicates that the point group symmetry of the dianion is only C2; the two- fold axis lies in the plane of the molecule. The dianion is twisted t o such an extent that even the four-membered ring is no longer planar (Fig. Ib). Steric hinderance does not

Fig. I . b) ORTEP representation of the dianion of 7a in the crystal; view along the two-fold axis.

lead, therefore, to a propeller-like arrangement of the sub- stituents but rather to a tetrahedral distortion. From the bond lengths of the endocyclic [(C-C)= 145.3(5) pm] and semicyclic C-C bonds [(C-C) = 138.7(9) pm], a n-bond character typical of pseudooxocarbon dianions compara- ble to that of squarates or tetrathiosquarates, can be de- rived"].

Received: June 9, 1981, in altered form: February 8, 1982 [ Z 36a IE] German version: Angew. Chem. 94 (1982) 290

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982. 582-589

[ I ] Review: G. Seitz, Nachr. Chem. Tech. Lab. 28 (1980) 804; R. West: Oxo-

131 G. Seitz, R. Matusch, K. Mann, them.-Zfg . 101 (1977) 557. [7] H. E. Sprenger, W. Ziegenbein, Angew. Chem. 79 (1967) 581; Angew.

181 T. Fukunaga, J. Am. Chem. SOC. 98 (1976) 610. [9] Cf. also a) S. Hiinig, H. Piitter, Chem. Ber. I10 (1977) 2524, 2532; b) G.

carbons. Academic Press, New York 1980.

Chem. Inr. Ed. Engl. 6 (1961) 553.

Seitz, R. Schmiedel, K. Mann, Chem.-Ztg. 99 (1975) 463.

Angew. Chem. Inr. Ed. Engl. 21 (1982) No. 4 0 Verlag Chemie GmbH. 6940 Weinheim. 1982 0570-0833/82/0404-0283 .$02.50/0 283