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Cyanogen as a Bridging LigandЧPreparation and Crystal Structure of Polymeric [Ag{(CN)2}2]n[AsF6]n with an Undulating Square Cationic Network.

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the diphenylmethylenefluorene 8a['31 via a Wittig-like
reaction. The cycloadduct 6b of b e n ~ a l d e h y d e ~and
' ~ ) 1 affords the olefin 8b at 110°C. Finally, it is interesting that
azides react with 1 at room temperature with evolution of
N2 to give the azaboriridines 7."'l
Experimental
1 : A solution of 2a (10.84 g, 32 mmol) in toluene (100 mL) was treated with
lithium rerr-butyl(trimethylsilyl)amide (5.25 g, 34.7 mmol) at room temperature under nitrogen. After 15 hours' stirring, the insoluble material was removed by centrifugation. On cooling the red solution to -25"C, plateletshaped crystals precipitated. To increase the yield the solution was then
cooled to -78°C and the solid isolated. The crystals, which are very sensitive to hydrolysis, effloresce on drying in a vacuum. Yield: 6.75 g (66%); m.p.
174- 176°C: "C-NMR (CDCI,, 243 K): S= 16.7, 32.9, 38.0, 56.6 (tmp); 83.2
(B-C), 119.8, 120.9, 121.1, 124.8, 133.0, 144.1 (fluorenyl moiety).
Received: January 25, 1985;
supplemented: February 19, 1985 [Z 1146 IE]
German version: Angew. Chem. 97 (1985) 424
CAS Registry numbers:
1, 96097-03-9; 2a, 96097-04-0; 2b, 96097-05-1 ; 4, 96097-06-2; 5, 96097-07-3:
6a, 96097-08-4; 6b, 96097-09-5; 7a, 96097-10-8; 7b, 96097-1 1-9; Sa, 470968-6; 8b, 1836-87-9; ((CH3)26CH2CH2CH2C(CH,)rkB=O),, 96097-12-0;
(CH,)2(?CH2CH2CH2C(CH,)*fiB=O,
96097-13-1;
PhN,,
622-37-7;
(CH&3iN3. 4648-54-8; Benzophenone, 119-61-9; Benzaldehyde, 100-52-7;
boron, 7440-42-8.
Systems with a high degree of double bonding include methyleneborates
(M. W. Rathke, R. Kow, J. Am. Chem. SOC.94 (1972) 6854; A. Pelter, B.
Singaram, L. Williams, J. W. Wilson, Tefrahedron Lett. 24 (1983) 623; A.
Pelter, B. Singaram, J. W. Wilson, ibid. 24 (1983) 635), bonnate anions
and their transition-metal complexes (G. E. Herberich, H. J. Becker, C .
Engelke, J . Organomel. Chem. 153 (1978) 265; G. E. Herberich, G.
Greiss, H. F. Heil, J. Miiller, Chern. Commun. 1971. 1328; G. E. Herberich, A. K. Naithani, J . Organomet. Chem. 241 (1983) t), as well as borabenzene- a n d horanaphthalene-pyridine (R. Boese, N. Finke, J. Henkelmann. G. Maier, P. Paetzold, H. P. Reisenauer, G. Schmid, Chem. Ber.
118 (1985) 1644), and a boranediylborirane (cf. IS]).
H. Noth, R. Staudigl, H.-U. Wagner, Inorg. Chem. 21 (1982) 706.
H . Noth, B. Rasthofer, S . Weber, Z . Nafurforxh. 8 3 9 (1984) 1058.
H. Noth, S . Weber, Z. Naturforsch. B38 (1983) 1460.
The "B nucleus in 1 is deshielded as compared to that in 2a and 2b
(6("B)=33.9 and 42.3, respectively); the chemical shift lies in the range
which is given for the three-coordinated boron in the boranediylborirane
[(CH3)3Si]2C-B(Si)(CH,),C=BC(CH3)3
(H. Klusik, A. Berndt, Angew.
Chem. 95 (1983) 8 9 5 ; Angew. Chem. Int. Ed. Engl. 22 (1983) 877
(6("B)= 52). Considering more recent theoretical results (P. H. M. Budzelaer, P. von R. Schleyer, W. Krogh-Jesperson, ibid. 96 (1984) 809 and
23 (1984) 825; G. Frenking, H. F. Schaefer 111, Chem. Phys. Lett. 109
(1984) 521) for this system and S("B) for 1, together with &("B)=3540 for bis(amino)boron(l +) cations the "B-NMR signal of the boranediylborirane at 6("B)=52 should be assigned to the boron atom with
the highest degree of B=C double bonding, and the signal at 6 = 18 to
the tetracoordinated boron. The signals of [R2N=B-RIe lie further
downfield [2], cf. B. Wrackmeyer, R. Koster in Houben-Weyl: Methoden
der organrschen Chemie, Bd. 13c. Thieme, Stuttgart 1984, p. 419.
B. Rasthofer, Dissertation, Universitat Miinchen 1984.
H . - 0 . Kalinowski, S . Berger, S . Braun: "C-NMR-Spekfroskopie,
Thieme, Stuttgart 1984.
These bands lie at higher frequency than those of the B=C double bond
in the boranediylborirane [ 5 ] (Raman bands 1675/1716 c m - ' ) but at
lower frequencies than v,,(N2B) (I8OO-l850 c m - ' ) of the (R2N)*B cations: ref. [2], and J. Higashi, A. D. Eastman, R. w. Parry, Inorg. Chem.
22 (1982) 716. Accordingly, the coupling of the equivalent BN and BC
stretching vibrations is not as strong as in the bis(amino)boron cations.
2b: m.p. 153-154OC; 6("B)=42.3; S(I3C) (CDC13)= 13.2, 32.7, 35.6,
55.9 (tmp), 48.5 (B-C), 119.9, 124.2, 126.2, 126.4, 142.1, 146.6 (fluorenyl).
4 : m.n. 103°C: S("B)=34.3:
,
,
. 6("C) (CDCI,)=
~
,15.0. 33.1.~ 36.3. 53.3
(Imp), 49.3 (OCH?), 44.3 ( B - 0 , 120.0, 124.3, 125.8, 126.7, 141.7, 146.7
(fluorenyl).
[ I l l 5 : m.p. 126°C; 6("B)=37.9: 6("C) (CDC13)=18.3, 28.5, 33.5, 41.8, 52.3
(tmp), 36.2, 42.0 (N(CHI)2), 46.5 ( B - 0 , 119.7, 124.8, 125.1, 126.2, 141.4,
148.3 (fluorenyl).
[I21 6a: m.p. 156°C (decomp.): 6("B)=36.9: S("C)(CDCI,)=16.4, 31.9,
39.9, 53.9 (Imp), 89.0 (0-0, 63.5 (B-c), 119.3, 125.6, 125.9, 126.2,
126.6, 127.2, 140.6, 145.6, 146.5 (aromat. C).-Monoclinic, space group
_I
Angew. Chem. Int. Ed. Engl. 24 11985) No. 5
I
_
I
P2,/c, a=12.910, b = 1 1 . 7 7 8 , c = I 8 . 6 7 8 ~ , ~ = 1 0 1 . 2 9 "Z, = 4 , R=0.0848
and R , =0.0776 for 3642 observed reflections, bond lengths in the fourmembered ring: BO 1.398(5), C O 1.457(4), CC 1.612(5), BC 1.624(5) A.
[I31 8a: m.p. 229°C (Lit. 228"C, M. Rabinowitz, 1. Agranat, E. D. Bergmann,
J. Chem. SOC.81967, 1281).
1141 6b: oil; 6("B)=36.6; S('H) (CDC13)=1.06 (6H), 1.10 (6H). 1.42 (m,
6H),6.00(1H),6.60-7.80(m,
13H).
[I51 7a: m.p. 151°C; 6("B)=21.3; 6("C) (CDCI,)= 16.8, 32.6, 39.2, 54.1
(Imp), 52.3 (B-c), 119.7, 119.9, 121.2, 121.3, 125.5, 126.2, 128.9, 139.1,
141.7, 147.7 (aromat. C).-7b:
m.p. 134°C; 6("B)=24.0; 6("C)
(CDCI,)= 17.3, 32.3, 39.6, 53.8 (tmp), 1.7 (Si(CH,),), 52.9 (B-c), 119.7,
121.2, 124.8, 125.9, 138.4, 150.7 (fluorenyl).
Cyanogen as a Bridging Ligand-Preparation and
Crystal Structure of Polymeric [Ag{(CN),J21,[AsF6In
with an Undulating Square Cationic Network
By Herbert W. Roesky,* Hartmut Hofmann,
Jiirgen Schimkowiak, Peter G . Jones, Karen Meyer-Base,
and George M . Sheldrick
Dedicated to Professor Rolf Sammet on the occasion of
his 65th birthday
Cyanogen has recently become of wide interest."] It can
be used in the preparation of a variety of heterocycles,
with the cyanogen usually remaining intact as an NCCN
synthetic unit. In some reactions, however, cleavage of the
C-C bond is observed, e.g., when cyanogen functions as a
cyanation reagent in the preparation of tetracyanoethene
from ethyne.I2I The reaction of cyanogen with sulfur in dimethylformamide in the presence of copper to give 1,2,4thiadia~ole-3,5-dicarbonitrile~~~
is also noteworthy. Common to these and other reactions of cyanogen is the active
participation of a metal center. The coordination of cyanogen to a metal and the resulting bonding must therefore
be of fundamental importance for the course of the catalytic reaction. We were interested therefore in obtaining
single crystals of coordination compounds of cyanogen.
Cyanogen is known to react with metal centers both to
form "end-on" complexes and to undergo oxidative addit i ~ n . ' By
~ . the
~ ~ reaction of excess cyanogen with the silver
salt 1 in liquid
we have succeeded, as far as we
know for the first time, in isolating and determining the
crystal structure of a cyanogen complex.
3 is colorless and water-sensitive and decomposes at
176°C. 2 remains as a linear unit in the reaction and is
present in 3 as a bridging ligand between silver atoms.
This construction makes possible a polymeric network in
which each silver atom is surrounded by four nitrogen
atoms in a square planar arrangement (Fig. 1). Only one
other example of this coordination geometry-in
Agl.,Mn8Ol6-is known for silver(~).[~I
Weak contacts to
the fluorine atoms (276 pm), which, however, can hardly
be viewed as covalent interactions, complete a distorted
octahedral coordination of the metal. The above-mentioned synthesis of 1,2,4-thiadia~ole-3,5-dicarbonitrile~~~
becomes more plausible on account of this study, since the
planar coordination of the silver by the cyanogen molecules also facilitates coordination to sulfur. It is unknown
[*I Prof. Dr. H. W. Roesky, Dr. H. Hofmann, J. Schimkowiak,
Dr. P. G. Jones, K. Meyer-Base, Prof. G. M. Sheldrick
lnstitut fur Anorganische Chemie der Universitat
Tammannstrasse 4, D-3400 Gottingen (FRG)
0 VCH Verlagsgesellschaji mbH. 0-6940 Weinheim. 1985
0570-0833/85/0505-0417 $ 02.50/0
411
at present how the sulfur is transferred to the cyanogen
molecule.
CAS Registry number:
3, 962 11-85-7
[I] H. W. Roesky, H. Hofmann, Chem.-Ztg. 108 (1984) 231.
121 G. Weddigen (BBC AG), DOS 3 127688 (July 14, 1981, Feb. 3, 1983):
Chem. Ahstr. 98 (1983) P142984n.
[ 3 ] H . W. Roesky, K. Keller, J. W. Bats,Angew. Chem. 95 (1983) 904;Angew.
Chem. I n t . Ed. Engl. 22 (1983) 8 8 1 ; Angew. Chem. Suppl. 1983, 1323.
[4] B. Corain, M. Basato, A. Warsone, Cltirn. Ind. 61 (1979) 567.
(51 B. Corain, Coord. Chem. Rev. 47(1982) 165.
[6] Liquid SO? (20 mL) is condensed at -78OC in a pressure vessel containing 1 (1.31 g, 4.4 mmol). The mixture is subsequently heated slowly with
stirring to room temperature in order to dissolve 1 homogeneously in
SO2. The mixture is cooled once again to -78"C, and 2 (1.38 g,
26.5 mmol) is condensed into the frozen solution. After thawing, the mixture is stirred for 2 h at room temperature. A light, crystalline precipitate,
moderately soluble in SOz, is formed. After filtration, SO, and excess 2
are slowly removed, yielding colorless crystals of 3, which are very watersensitive. Yield of 3 : 0.37 g (21%): IR (Nujol): v=2200, 2125, 695. and
380 c m - ' (cf. C N stretching vibration of gaseous 2 at 2157 cm-'). Strong
Raman bands at 2356, 872, 688, 510, and 370 cm-'.
[7] F. M. Chang, M. Jansen, Angew. Chem. 96 (1984) 902; Angew. Chenz. Int.
Ed. Engl. 23 (1984) 906.
Gas-Phase Reactions of Organic Compounds on
Raney Nickel**
By Hans Bock* and Hans Peter Wow
Dedicated to Professor Gunther Wilke on the occasion
of his 60th birthday
Fig. 1. Above: perspective view of the polymeric layer cation of 3 in the crystal. C2/m, a=866.5(4), 6=836.3(3), e=819.8(4) pm, B= 122.06(3)", Z = 2
(monomers), T = - 40°C. MoKnr28,,, = 55". R = 0.039, R , = 0.043 for 550 reflections (corrected for absorption) with F > 4 o ( F ) . All atoms of the cation lie
on special positions; Ag on 0, 0 , O ; C I and NI on x, 0, z ; C2 and N2 on 0, y ,
0. The refinement was difficult because of pseudosymmetry (all reflections
with odd I are weak) and disorder of the anion. Important bond distances
[pm] and bond angles I"]: Ag-Nl 239.9(6), Ag-N2 236.4(7), N1-CI
113.8(9), N2-C2
112.8(10), CI-CI'
138.0(12), C2-C2'
137.9(14);
Ag-NI-Cl
152.3(9), Nl-CI-CI'
177.9(14), all other angles 90 or 180".
(CI' and C2' are equivalent atoms generated by inversion symmetry). The
transformation matrix 0- 1 0/- 1 0 O/ - 1 0 - 2 generates an apparently Fcentered orthorhombic cell (a'=836.3, b'=866.S, c ' = 1389.7 pm), which however, exhibits only monoclinic Laue symmetry. Below: projection of the
structure of 3 along the h axis (N2 and C2 lie on this axis and are therefore
difficult to recognize). The layers are clearly undulating with an Ag-NI-CI
angle of 152.3". Only one orientation of the disordered anion is shown. The
As atom lies on 0, 0, f, the F atoms, however, on general positions. Open
circles: large, Ag: medium, N ; small, C ; cross-hatched circles, As: black
points, F. Further details of the crystal structure investigation are available
on request from the Fachinformationszentrum Energie Physik Mathematik,
D-7514 Eggenstein-Leopoldshafen 2, on quoting the depository number
CSD 51 252, the names of the authors, and the journal citation.
Received: January 28, 1985;
revised: February 15, 1985 [ Z I148 IE]
German version: Angew. Chem. 97 (1985) 403
41 8
0 VCH Verlagsgesei~schajimbH, D-6940 Weinheim, 1985
Raney nickel, used advantageously both in industry1'"'
and in the laboratoryf2" as an active catalyst for liquidphase hydrogenations, is prepared from Ni/AI alloys using
concentrated caustic soda."' Physical investigations['] have
shown that the largely uniform network of pores provides
surface areas of up to 100 m2/g, depending on the method
of preparation, and contains regions of ordered Ni crystals. Moreover, the Al component affects not only the texture but also functions as an electron donor to the Ni(3d)
band. We report here the reactions of gaseous organic
compounds on solid Raney nickel."] In comparison with
the pyrolysis of such compounds on quartz wool or the catalytic decomposition on nickel turnings, these reactions
take place at much lower temperatures with marked selectivity.
The following model reactions were studied in a horizontally arranged solid-bed reactor by PE spectroscopic
analysis14' of the gas flow (see Fig. 1): the dehydrogenation
of 2-propanol, which competes with its dehydration; the
decarbonylation of methyl formate, and the elimination of
N 2 from methyl diazoacetate [Reactions (a)-(e)].
Hz
+ (H,C),C=O
(a)
HzO
+ H,C-HC=CH>
(b)
+ H,COH 2CO + 2H7
(C)
NZ
+ CO f H,C-CHO
(d)
N2
+ H,COOCHC=CHCOOCH? ( e )
(H3C)ZCHOH
HCOOCH,
A CO
NN=CH-COOCH?
[*I Prof. Dr. H. Bock, Dipl.-Chem. H. P. Wolf
Institut fur Anorganische Chemie der Universitat
Niederurseler Hang, D-6000 Frankfurt am Main 50 (FRG)
[**I Gas-phase reactions, Part SO. This work was supported by the Land
Hessen, the Deutsche Forschungsgemeinschaft, and the Fonds der
Chemischen Industrie. Part 49: H. Bock, B. Solouki, G. Maier, Angew.
Chem. 97 (1985) 205; Angew. Chem. Int. Ed. Engl. 24 (1985) 205.
0570-0833/85/0505-0418 $ 02.50/0
Angew. Chem. Inr. Ed. Engl. 24 (198s) No. 5
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