Synthesis, properties, and solid-state structures of bis(alkyne)metal(0) complexes (metal = Ni, Pt) with substituted alkynediols and alkynols

Article abstract of DOI:10.1021/om950896u

A variety of tetrasubstituted alkynediols react with (cdt)Ni (cdt = 1.5.9-cyclododecatriene) to give the homoleptic (alkyne)nickel complexes (HOR¹R²CC≡CCR¹R²OH) ₂Ni as yellow crystals that are stable in the solid state at room temperature (R¹ = R² = Et, 1; R¹ = Me, = R² = Et, 2; R¹ = Me, R² = Pr, 3; R¹ = R² = -(CH₂)₅-, 4; R¹ = Me, R² = i-Bu, 5). The ¹³C-NMR spectra show resonances for the coordinated alkyne carbon nuclei in the 133.5-135.2 ppm region. Only one resonance was found for 1-4 indicating a symmetrical structure. More than one resonance was found for 5 as well as for its platinum analog, compound 8, indicating the presence of different isomeric bis(alkyne)metal complexes. The structure of 1 has been established by single-crystal X-ray diffraction. The central atom is tetrahedrally coordinated to the four carbon atoms of two terminal alkynes. The network of hydrogen bonding between the four OH groups of neighboring molecules, which consists exclusively of intermolecular hydrogen bonds, stabilizes the crystal structure yielding a polymer-like chain. The platinum complex 9 (R¹ = R² = Me) shows similar structural properties. The reaction of (cdt)Ni or (cod)₂Pt (cod = 1.5-cyclooctadiene) with the substituted alkynols R₃CC≡CCR¹₂OH yields the new bis(alkyne)metal(0) compounds 10 (M = Ni, R = Me, R¹ = Me), 11 (M = Pt, R = Me, R¹ = Me), and 12 (M = Ni, R = Me, R¹ = Et). Single-crystal X-ray structure determinations of 10-12 reveal that the central metal atoms are tetrahedrally coordinated by the four carbon atoms of the alkyne ligands. Two (alkyne)₂M units are connected via hydrogen bonds between the four OH groups to form a dimer in the solid state. Complex 10 reacts in solution below -15°C to yield the trimeric complex (alkyne)₄Ni₃.

Full text of DOI:10.1021/om950896u

2314
Organometallics 1996, 15, 2314-2319
Syn th esis, P r op er ties, a n d Solid -Sta te Str u ctu r es of
Bis(a lk yn e)m eta l(0) Com p lexes (Meta l ) Ni, P t) w ith
Su bstitu ted Alk yn ed iols a n d Alk yn ols
Dirk Walther,* Thomas Klettke, and Andreas Schmidt
Institut fu¨r Anorganische und Analytische Chemie der Universita¨t, August-Bebel-Strasse 2,
07743 J ena, Germany
Helmar Go¨rls and Wolfgang Imhof
Max-Planck-Arbeitsgruppe CO2-Chemie an der Universita¨t, 07743 J ena, Germany
Received November 20, 1995X
A variety of tetrasubstituted alkynediols react with (cdt)Ni (cdt ) 1.5.9-cyclododecatriene)
to give the homoleptic (alkyne)nickel complexes (HOR1R2CCtCCR1R2OH)2Ni as yellow
crystals that are stable in the solid state at room temperature (R1 ) R2 ) Et, 1; R1 ) Me, R2
) Et, 2; R1 ) Me, R2 ) Pr, 3; R1 ) R2 ) -(CH2)5-, 4; R1 ) Me, R2 ) i-Bu, 5). The 13C-NMR
spectra show resonances for the coordinated alkyne carbon nuclei in the 133.5-135.2 ppm
region. Only one resonance was found for 1-4 indicating a symmetrical structure. More
than one resonance was found for 5 as well as for its platinum analog, compound 8, indicating
the presence of different isomeric bis(alkyne)metal complexes. The structure of 1 has been
established by single-crystal X-ray diffraction. The central atom is tetrahedrally coordinated
to the four carbon atoms of two terminal alkynes. The network of hydrogen bonding between
the four OH groups of neighboring molecules, which consists exclusively of intermolecular
hydrogen bonds, stabilizes the crystal structure yielding a polymer-like chain. The platinum
complex 9 (R1 ) R2 ) Me) shows similar structural properties. The reaction of (cdt)Ni or
(cod)2Pt (cod ) 1.5-cyclooctadiene) with the substituted alkynols R3CCtCCR1 OH yields the
2
new bis(alkyne)metal(0) compounds 10 (M ) Ni, R ) Me, R1 ) Me), 11 (M ) Pt, R ) Me, R1
) Me), and 12 (M ) Ni, R ) Me, R1 ) Et). Single-crystal X-ray structure determinations of
10-12 reveal that the central metal atoms are tetrahedrally coordinated by the four carbon
atoms of the alkyne ligands. Two (alkyne)2M units are connected via hydrogen bonds between
the four OH groups to form a dimer in the solid state. Complex 10 reacts in solution below
-15 °C to yield the trimeric complex (alkyne)4Ni3.
In tr od u ction
Very recently we were able to synthesize the first
crystalline bis(alkyne)nickel(0) complex, (2,5-dimethyl-
hex-3-yne-2,5-diol)2Ni, which was structurally charac-
terized by single-crystal X-ray diffraction.10
By using 2-methyl-5,5-dimethylhex-3-yn-2-ol as the
ligand, we also were able to isolate the trimeric homo-
leptic alkyne complex (alkyne)4Ni3, which contains two
bridging alkyne ligands.11 In both complexes the OH
groups are tolerated by the low-valent nickel atom and
appear to be very important in stabilizing the structure
in the solid state.
In this paper we will show that homoleptic bis-
(alkyne)Ni compounds can be isolated with a wide
variety of different alkynes although one requirement
is that they possess OH groups. In order to determine
whether one central metal atom was unique in deter-
mining the structure of these novel materials, two new
platinum complexes also were prepared. One goal of
this investigation was to study the molecular assembly
The simplest stable homoleptic (alkyne)metal com-
pounds of the type (alkyne)2M(0) are of interest not only
as starting materials for organometallic reactions, in
particular for catalytic processes, but also as model
compounds for understanding the interaction of alkynes
with metal surfaces. Until 1994, only platinum com-
plexes of this type were known,1-4 partly because
attempts to isolate bis(alkyne)nickel(0) complexes had
been unsuccessful.5,6 However, some cyclotriynes have
been shown to react with (cod)2Ni (cod ) 1.5-cycloocta-
diene) to give nickel(0) complexes in which the central
atom is coordinated to the three alkyne moieties of the
macrocycles.7-9
X Abstract published in Advance ACS Abstracts, March 15, 1996.
(1) Rochon, F. D.; Theophanides, T. Can. J . Chem. 1972, 50, 1325-
1330.
(2) Dubey, R. J . Acta Crystallogr. 1975, B31, 1860-1864.
(3) Boag, N. M.; Green, M.; Grove, D. M.; Howard, J . A. K.; Spencer,
J . L.; Stone, F. G. A. J . Chem. Soc., Dalton Trans. 1980, 2170-2181.
(4) Boag, N. M.; Green, M.; Howard, J . A. K.; Stone, F. G. A.;
Wadepohl, H. J . Chem. Soc., Dalton Trans. 1981, 862-872.
(5) Muetterties, E. L.; Pretzer, W. R.; Thomas, M. G.; Beier, B. F.;
Thorn, D. L.; Day, W.; Anderson, A. B. J . Am. Chem. Soc. 1978, 100,
2090-2096.
(8) Youngs, W. J .; Kinder, J . D.; Bradshaw, J . D.; Tessier, C. A.
Organometallics 1993, 12, 2406-2407.
(9) Guo, L.; Bradshaw, J . D.; Tessier, C. A.; Youngs, W. J . Organo-
metallics 1995, 14, 586-588.
(10) Walther, D.; Schmidt, A.; Klettke, T.; Go¨rls, H.; Imhof, W.
Angew. Chem. 1994, 106, 1421-1424; Angew. Chem., Int. Ed. Engl.
1994, 33, 1373-1376.
(6) Ozin, G. A.; McIntosh, D. F.; Power, W. J .; Messmer, R. P. Inorg.
Chem. 1981, 20, 1782-1792.
(7) Ferrera, J . D.; Tanaka, A. A.; Fierro, C.; Tessier-Youngs, C. A.;
Youngs, W. J . Organometallics 1989, 8, 2089-2098.
(11) Walther, D.; Klettke, T.; Go¨rls, H. Angew. Chem. 1995, 107,
2022-20234; Angew. Chem., Int. Ed. Engl. 1995, 37, 1860-1861.
S0276-7333(95)00896-X CCC: $12.00 © 1996 American Chemical Society

Bis(alkyne)metal(0) Complexes
Organometallics, Vol. 15, No. 9, 1996 2315
Ta ble 1. Selected IR- a n d 13C-NMR Va lu es a n d Decom p osition Tem p er a tu r es for
(HOR1R2CCtCCR1R2OH)2Ni (1-5)
decomposn
pt (°C)
compd
alkyne
νCtC (cm-1
)
δCt (ppm)
134.3
133.5
134.5
135.0
1
2
3
4
HOEt2CCtCCEt2OH
HOMe(Et)CCtCC(Et)MeOH
HOMe(Pr)CCtCC(Pr)MeOH
1904
1889
1887
1882
173
132
119
141
HO
OH
5
HOMe(i-Bu)CCtCC(i-Bu)MeOH
1885
134.8-135.2a
88
a
6 signals.
and intermolecular interactions present in the crystals
in order to understand the role of the OH groups in
stabilizing the crystalline structure.
Resu lts a n d Discu ssion s
The reaction of (cdt)Ni with many substituted alkyne-
diols in THF at -40 °C leads to the formation of the
homoleptic (alkyne)2Ni complexes according to eq 1. The
(cdt)Ni + 2HOR1R2CCtCCR1R2OH f
(HOR1R2CCtCCR1R2OH)2Ni + cdt
compounds 1-5 (see Table 1) could be isolated as pure
crystalline compounds. At low temperatures there is
no evidence for C-C linkage of the alkynes at the low-
valent nickel center.
In contrast, the reaction of (cod)2Ni with 2,4,7,9-
tetramethyldec-5-yne-4,7-diol and the reaction of (cod)2Ni
with 3,6-diethyloct-4-yne-3,6-diol results in the forma-
tion of the mixed-ligand complexes (cod)Ni(alkyne), 6
and 7, while 2,5-dimethylhex-3-yne-2,5-diol yields the
corresponding (alkyne)2Ni compound.10 There are two
possible routes for the formation of 6 and 7 from
(cod)2Ni: on one hand a substitution of a cyclooctadiene
ligand against an alkyne and on the other hand the
intermediate formation of the bis(alkyne)nickel complex
and a subsequent syn-proportionation reaction with
(cod)2Ni.
The solid yellow compounds 1-5 (Table 1) are stable
at room temperature and extremely sensitive toward air
and moisture. They are insoluble in pentane but can
be dissolved in polar solvents such as THF or DMF.
However, their solubility and stability in these solutions
is quite poor at room temperature and depends on the
size of the R groups. The larger the R group the more
soluble and stable in solution is the alkyne complex. The
13C-NMR spectra (see Experimental Section) show that
the signals of 1-5 for coordinated alkyne carbon atoms
are located in the 133.5-135.2 ppm region, a shift of
about 47 ppm downfield compared to the corresponding
free alkynes. The tertiary carbon signals for the coor-
dinated alkynes shift about 3 ppm downfield as opposed
to the free alkyne. The spectra of 1-4, which contain
alkynes with unbranched alkyl groups, clearly show
that the alkynes are symmetrically coordinated around
the central metal atom. Only one resonance for the
alkyne carbon nuclei and one resonance for the tertiary
carbon atoms are observed. The 13C-NMR spectrum of
the (alkyne)2Ni complex 5 (R1 ) Me, R2 ) i-Bu) is more
complicated. In the region of the signals for the carbons
of the CtC triple bond a series of resonances is observed
between 134.8 and 135.2 ppm (see Table 1) indicating
F igu r e 1. (a) Top: Solid-state structure of (Et2(OH)CCt
CC(OH)Et2)2Ni, 1. (b) Bottom: Supramolecular structure
of (Et2(OH)CCtCC(OH)Et2)2Ni, 1. O-O ) 2.889, 2.937 Å;
ethyl groups have been omitted for clarity.
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of (Et2(OH)CCtCC(OH)Et2)2Ni, 1a
Ni-C(1)
C(1)-C(2)
1.875(1)
1.494(2)
C(1)-C(1C)
1.259(3)
C(1)-Ni-C(1A)
C(1)-Ni-C(1C)
C(1C)-C(1)-Ni
153.08(8)
39.23(8)
70.39(4)
C(1)-Ni-C(1B)
C(2)-C(1)-C(1C)
C(2)-C(1)-Ni
152.01(8)
155.34(6)
134.25(9)
a
Angle between planes (deg): [Ni-C(1)-C(1C)]-[Ni-C(1A)-
C(1B)] ) 87.81.
the existence of structurally similar isomers in solution.
These signals do not split at lower temperatures ([D8]-
THF, -60 °C, 50.3 MHz) and do not collapse at higher
temperatures ([D8]THF, +40 °C, 50.3 MHz). The cor-
responding platinum complex, 8, exhibits the same type
of 13C-NMR spectrum.
The infrared specta of 1-5 show the bands assigned
to the stretching vibrations of coordinated CtC bonds
in the 1882-1904 cm-1 region (Table 1). The IR- and
13C-NMR spectroscopic data correspond well with those
of the described bis(alkyne)platinum compounds.3
The single-crystal X-ray structure determination of
1 (Table 5) confirms the expected tetrahedral geometry
around the nickel(0) center (Figure 1a). Selected bond
lengths and angles are tabulated (Table 2). The nickel
atom is situated on the intersection of three crystal-
lographic 2-fold axes. Therefore, only the nickel atom
itself and half of one of the alkyne ligands are located

2316 Organometallics, Vol. 15, No. 9, 1996
Walther et al.
by X-ray structure analysis, whereas the rest of the
molecule is generated by symmetry operations. The
Ni-C and CtC bond lengths show values typical of the
known (alkyne)Ni complex with 2,5-dimethylhex-3-yne-
2,5-diol as the alkyne ligand.10 Figure 1b shows the
view of the supramolecular structure of 1. Polymeric
chains that are independent of each other exist. In
these chains O4-tetrahedrons are built up via four
intermolecular hydrogen bonds which link adjacent
molecules. This kind of supramolecular structure was
also found in the analogous platinum compound2 and
in the complexes (HOMe2CCtCMe2OH)2M (M ) Ni,
10;10 M ) Pt, 9; see Table 5) and seems to be a general
stabilizing principle in the solid-state structures of
(alkynediol)2M complexes. In bis(alkyne)metal com-
plexes containing alkynols only two OH groups are
present. The questions then arise whether low-valent
metal complexes of such acetylenes can be synthesized
and would these have a similar type of supramolecular
structure.
The reaction of 1 molar equiv of (cdt)Ni with 2 equiv
of 2-methyl-5,5-dimethylhex-3-yn-2-ol in pentane yields
at room temperature quantitatively the complex (al-
kyne)2Ni, 10, in solution, which was identified by its IR
spectrum (ν(CtC) ) 1892 cm-1), 1H-NMR spectrum,
and 13C-NMR spectrum (133.2 and 136.5 ppm for
coordinated alkyne-carbon atoms). No signals were
observed for bridging alkynes or coordinated cdt at room
temperature. These results show that at room temper-
ature no detectable quantities of other (alkyne)Ni
complexes are present in solution, because only one set
of signals indicative of only one kind of coordinated
alkyne is observed. Surprisingly at -78 °C the trimeric
complex (alkyne)4Ni3 crystallizes from the solution11 as
a result of an aggregation process at low temperature
according to eq 2. Small quantities of 10 can be isolated
F igu r e 2. (a) Top: Solid-state structure of (Me3CCtCC-
(OH)Me2)2Ni, 10. (b) Bottom: Supramolecular structure
of (Me3CCtCC(OH)Me2)2Ni, 10. O-O ) 2.816, 2.775 Å;
methyl groups have been omitted for clarity.
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of (Me3CCtCC(OH)Me2)2Ni, 10a
Ni-C(1)
C(1)-C(2)
C(2)-C(3)
1.888(2)
1.260(4)
1.499(4)
Ni-C(2)
C(1)-C(6)
1.881(2)
1.498(4)
3(alkyne)2Ni h (alkyne)4Ni3 + 2alkyne
C(1)-Ni-C(2)
C(1)-Ni-C(1A)
C(1)-Ni-C(2A)
C(1)-C(2)-Ni
Ni-C(2)-C(3)
C(2)-C(1)-C(6)
39.0(1)
155.6(2)
153.4(1)
70.8(2)
133.9(2)
152.5(3)
Ni-C(1)-C(2)
C(2)-Ni-C(2A)
C(2)-Ni-C(1A)
Ni-C(1)-C(6)
C(1)-C(2)-C(3)
70.2(2)
147.7(2)
153.4(1)
136.9(2)
154.9(2)
from a pentane/THF solution (100/1) at -78 °C as yellow
crystals. These are stable under argon at low temper-
ature. The existence of different homoleptic (alkyne)-
nickel complexes with the same alkyne leads us to
conclude that only small energy differences exist be-
tween the different alkyne nickel species and that the
ligand and the crystallization conditions have a decisive
influence on the composition of the (alkyne)nickel(0)
complexes that can be isolated.
a
Angle between plane (deg): [Ni-C(1)-C(2)]-[Ni-C(1A)-
C(2A)] ) 94.33.
complex (alkyne)2Ni, 12, as yellow crystals that are
stable in the solid state under argon at low tempera-
tures. In the IR spectrum of 12 the band for the CtC
stretching vibration appears at 1901 cm-1. The 13C-
NMR signals for the carbon atoms of the coordinated
alkynes are observed at 128.5 and 138.2 ppm. By using
diethyl ether as the solvent, single crystals of 12 suitable
for single-crystal X-ray structural analysis were ob-
tained at -78 °C (Table 5). Complex 12 shows the
anticipated structural features; namely, the nickel atom
is tetrahedrally coordinated by the four alkyne-carbon
atoms with typical bond distances and angles (Figure
3a; for selected values, see Table 4). The tertiary butyl
group of one of the alkyne ligands is disordered. The
supramolecular structure shows that dimers as de-
scribed for 10 and 11 are formed (Figure 3b). The (cod)-
Ni(alkynediol) complexes 6 and 7 are yellow-orange, air-
sensitive compounds. Their X-ray structure investi-
gations (Table 5) show the same type of hydrogen-
The result of the solid-state study of 10 (Table 5) is
shown in Figure 2a. Selected interatomic distances and
angles are listed in Table 3. Yet again the metal atom
is tetrahedrally coordinated by the four alkyne-carbon
atoms. The observed values for the CtC bond lengths
correspond to those of 1. 10 crystallizes as a dimer, via
four hydrogen bonds in which the oxygen atoms each
occupy a corner of a “square”. The oxygen atoms of any
one molecule lie diagonal with respect to each other so
that no intramolecular hydrogen bond can be formed
(Figure 2b). A very similar structure was found for the
corresponding platinum complex 11 (Table 5), which
results from the reaction of (cod)2Pt with 2-methyl-5,5-
dimethylhex-3-yn-2-ol. Its IR- and 13C-NMR data are
also very similar to those of 10: ν(CtC) ) 1889 cm-1
;
δ(Ct) 127.8 and 131.9 ppm. The reaction of 3-ethyl-
6,6-dimethylhept-4-yn-3-ol with (cdt)Ni yields the

Bis(alkyne)metal(0) Complexes
Organometallics, Vol. 15, No. 9, 1996 2317
Exp er im en ta l Section
All operations were carried out in an argon atmosphere
using standard Schlenk and vacuum techniques. THF, diethyl
ether, and hydrocarbon solvents were dried and distilled from
sodium diphenyl ketyl. The NMR solvents were dried in the
same way. The alkynes were prepared according to the
literature procedures from Li2C2 and the ketone or by the
reaction of commercial monosubstituted acetylenes with bu-
tyllithium and the ketone.12,13
(cdt)Ni and (cod)2Pt were prepared as described.14,15
The 200 MHz 1H- and 50.3 MHz 13C-NMR spectra were
recorded on a Bruker AC 200 spectrometer. The 400 MHz 1H-
and 100.6 MHz 13C-NMR spectra were recorded on a Bruker
DRX 400 spectrometer. Infrared spectra were recorded on a
Perkin-Elmer FT-IR system working quickly with a Nujol mull
between KBr plates.
Single-crystal X-ray structure determinations were carried
out at low temperature on an Enraf-Nonius CAD4 diffracto-
meter; the structures were solved by direct (1, 6, 7, 10, 12) or
Patterson methods (9, 11), respectively, followed by least-
squares refinement using the programs SHELX-86 and
SHELXL-93.16 Computation of the structures was done with
the program XPMA, and the molecular illustrations were
drawn using the program ZORTEP.17 The crystal and inten-
sity data of 1, 6, 7, and 9-12 are given in Table 5.
Nick el Com p ou n d s. (3,6-Dieth yloct-4-yn e-3,6-d iol)2Ni,
1. A 2.37 mmol (0.532 g) amount of (cdt)Ni and 4.73 mmol
(0.937 g) of 3,6-diethyloct-4-yne-3,6-diol were mixed in 50 mL
of THF at -40 °C. The solution was allowed to reach room
temperature and was then filtered, whereupon 30 mL of
hexane was added. At room temperature 1 precipitated as
yellow needles. Single crystals were obtained from DMF.
Yield: 2.09 mmol (0.95 g); 88.2%. Anal. Calc for C24H44O4Ni:
Ni, 12.89. Found: Ni, 12.76. IR (Nujol): 1904 (s, CtC), 3400
F igu r e 3. (a) Top: Solid-state structure of (Me3CCtCC-
(OH)Et2)2Ni, 12. (b) Bottom: Supramolecular structure of
(Me3CCtCC(OH)Et2)2Ni, 12. O-O ) 2.788, 2.807 Å;
methyl and ethyl groups have been omitted for clarity.
(s, OH) cm-1 1H-NMR ([D7]DMF, 35 °C, 50.3 MHz): δ 0.99
.
(m, CH3, 24 H), 1.67 (m, CH2, 16 H). 13C-NMR ([D7]DMF, 35
°C, 200 MHz): δ 9.1 (CH3), 35.4 (CH2), 74.3 (CEt2OH), 133.3
(Ct). Decomposn pt ) 173 °C.
Ta ble 4. Selected Bon d Len gth s (Å) a n d An gles
(d eg) of (Me3CCtCC(OH)Et2)2Ni, 12
Ni-C(1)
1.874(4)
1.882(4)
1.259(5)
1.485(5)
1.501(5)
Ni-C(2)
1.875(4)
1.880(4)
1.250(5)
1.510(5)
1.493(5)
(3,6-Dim eth yloct-4-yn e-3,6-d iol)2Ni, 2. A 1.22 mmol
(0.270 g) amount of (cdt)Ni and 2.44 mmol (0.410 g) of 3,6-
dimethyloct-4-yne-3,6-diol were mixed at -40 °C in 40 mL of
THF. After being warmed to room temperature, the mixture
was filtered and 30 mL of hexane was added. At 25 °C 2
crystallized in the form of yellow needles. Yield: 0.72 mmol
(0.281 g); 59.0%. Anal. Calc for C20H36O4Ni: C, 60.27; H, 9.11;
Ni, 14.55. Found: C, 60.36; H, 8.75; Ni, 14.62. IR: 1889 (s,
Ni-C(12)
C(1)-C(2)
C(1)-C(7)
C(12)-C(18)
Ni-C(13)
C(12)-C(13)
C(2)-C(3)
C(13)-C(14)
C(1)-Ni-C(2)
C(1)-Ni-C(12)
C(7)-C(1)-C(2)
Ni-C(12)-C(13)
39.2(2) Ni-C(1)-C(2)
150.3(2) C(2)-Ni-C(13)
155.5(4) C(3)-C(2)-C(1)
70.5(2)
152.8(2)
154.6(4)
70.5(2) C(18)-C(12)-C(13) 155.6(4)
CtC), 3306 (s, OH) cm-1
.
1H-NMR ([D7]DMF, 200 MHz, 25
C(14)-C(13)-C(12) 156.8(4)
°C): δ 0.98 (t, CH3, 12 H), 1.54 (s, CH3, 12 H), 1.68 (q, CH2, 8
H), 4.74 (s, OH, 4 H). 13C-NMR ([D7]DMF, 25 °C, 50.3 MHz):
δ 9.3 (CH3), 30.4 (CH3), 36.4 (CH2), 70.6 (CMeEtOH), 133.5
(Ct). Decomposn pt ) 132 °C.
(4,7-Dim eth yldec-5-yn e-4,7diol)2Ni, 3. A 1.49 mmol (0.330
g) amount of (cdt) Ni and 2.99 mmol (0.598 g) of 4,7-
dimethyldec-5-yne-4,7-diol were dissolved at -40 °C in a
mixture of 15 mL of diethyl ether and 10 mL of THF. After
being warmed to room temperature, the mixture was filtered.
At room temperature 3 crystallized in the form of yellow
needles. Yield: 0.68 mmol (0.375 g); 45.3%. Anal. Calc for
a
Angle between plane (deg): [Ni-C(1)-C(2)]-[Ni-C(12)-
C(13)] ) 94.78.
bonded network as described for the mixed-ligand
complex (cod)Ni(2,5-dimethylhex-3-yn-2,5-diol).10
Su m m a r y
From this study we can conclude the following: (i)
(alkyne)2Ni complexes are quite stable in the solid state
because they are stabilized by hydrogen bonds between
the OH groups of neighboring molecules. (ii) In each
Ni or Pt complex that was investigated by single-crystal
X-ray diffraction four OH groups from neighboring
alkynes are responsible for the same type of hydrogen-
bonded network. This network is set up by four
intermolecular hydrogen bonds. When the ligands are
alkynediols, this feature leads to the formation of
polymeric chains, whereas when alkynols are used,
dimeric complexes are formed. (iii) Only small energy
differences exist between the complexes (2-methyl-5,5-
dimethylhex-3-yn-2-ol)4Ni3 and (2-methyl-5,5-dimeth-
ylhex-3-yn-2-ol)2Ni. Both complexes can be isolated.
C
24H44O4Ni: C, 63.40; H, 9.76; Ni, 12.75. Found: C, 63.19;
H, 10.04; Ni, 12.70. IR: 1887 (s, CtC), 3286 (s, OH) cm-1
.
(12) Midland, M. M. J . Org. Chem. 1975, 40, 2250-2252.
(13) Smith, W. N.; Kuehn, E. D. J . Org. Chem. 1973, 38, 3588-
3591.
(14) Bogdanovic, B.; Kro¨ner, M.; Wilke, G. J ustus Liebigs Ann. 1966,
699, 19.
(15) Herberich, G. E.; Hessner, B. Z. Naturforsch. 1979, 34b, 638-
639.
(16) (a) Sheldrick, G. SHELXS-86, Universita¨t Go¨ttingen, 1986. (b)
Sheldrick, G. SHELXL-93, Universita¨t Go¨ttingen, 1993.
(17) (a) Zsolnai, L. XPMA, Universita¨t Heidelberg, 1994. (b) Zsolnai,
L.; Pritzkow, H. ZORTEP, Universita¨t Heidelberg, 1994.
(18) Parkin, S.; Moezzi, B.; Hope, H. J . Appl. Crystallogr. 1995, 28,
53-56.

2318 Organometallics, Vol. 15, No. 9, 1996
Walther et al.
Ta ble 5. Cr ysta l a n d In ten sity Da ta for th e Com p ou n d s (Et2(OH)CCtCC(OH)Et2)2Ni, 1,
(iBu Me(OH)CCtCC(OH)MeiBu )Ni(cod ), 6, (Et2(OH)CCtCC(OH)Et2)Ni(cod ), 7, (Me2(OH)CCtCC(OH)Me2)2P t,
9, (Me3CCtCC(OH)Me2)2Ni, 10, (Me3CCtCC(OH)Me2)2P t, 11, a n d (Me3CCtCC(OH)Et2)2Ni, 12
compd
1
6
7
9
10
11
12
formula
Mr
C
455.3
24H44O4Ni
C22H38O2Ni
393.2
C20H34O2Ni
365.2
C16H28O4Pt
479.4
C18H32O2Ni
339.2
C18H32O2Pt
475.5
C22H40O2Ni
395.2
radiation
monochromator
temp (K)
cryst color
cryst size (mm)
Mo KR
graphite
183
yellow
0.4 × 0.4 ×
0.3
Mo KR
graphite
183
yellow
0.4 × 0.2 ×
0.2
Mo KR
graphite
193
yellow
0.6 × 0.4 ×
0.1
Mo KR
graphite
183
colorless
0.3 × 0.2 ×
0.15
Mo KR
graphite
183
yellow
0.4 × 0.4 ×
0.4
Mo KR
graphite
183
colorless
0.8 × 0.6 ×
0.3
Mo KR
graphite
183
yellow
0.4 × 0.3 ×
0.3
a (Å)
b (Å)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
8.9050(1)
21.660(2)
26.002(5)
90
90
90
13.581(1)
15.002(2)
10.451(2)
90
92.55(5)
90
10.729(2)
9.564(3)
20.102(4)
90
102.18(2)
90
15.30(1)
8.830(4)
15.471(6)
90
108.37(2)
90
13.610(1)
14.332(2)
40.972(4)
90
90
90
13.396(5)
14.124(8)
21.91(2)
90
107.67(2)
90
25.166(5)
9.618(2)
22.851(5)
90
118.70(3)
90
5015(1)
8
2127.2(5)
4
2016.3(8)
4
1984(2)
4
7991(1)
16
3950(5)
8
4851(1)
8
F(000)
F
cryst system
space group
abs coeff (mm-1
abs corr
1984
1.206
orthorhombic
Fddd
0.798
856
1.228
monoclinic
C2/c
0.924
792
1.203
monoclinic
P21/c
0.997
936
1.605
monoclinic
Cc
2944
1.127
orthorhombic
Fddd
0.973
1872
1.599
monoclinic
C2/c
1728
1.082
monoclinic
C2/c
0.810
calc (g cm-3
)
)
7.083
7.107
XABS218
0.831-1.245
2.70-23.56
ω-2θ
XABS218
0.846-1.152
1.95-25.00
ω-2θ
min-max transm
θ limit (deg)
2.45-27.41
ω-2θ
1-10
1433
2.02-25.04
ω-2θ
1-10
1954
1.94-23.96
ω-2θ
1-10
3828
2.55-27.42
ω-2θ
1-10
4556
2.70-27.44
ω-2θ
1-10
5649
scan mode
scan speed (deg min-1
refl measd
)
1-10
2304
1-10
3571
indepdt refl.
1433
1871 (R )
0.0680)
1748
188
1.153
0.0344
0.1023
0.425
2834 (R )
0.0453)
2390
344
0.876
0.0294
0.0665
0.316
1540 (R )
0.0570)
1427
190
1.157
0.0501
0.1286
2.260
2286 (R )
0.0412)
1632
104
1.157
0.0366
0.0974
0.739
3471 (R )
0.0903)
2867
197
1.153
0.0570
0.1573
2.541
5525 (R )
0.0587)
3376
236
1.281
0.0578
0.1411
0.847
2
2
obs refl Fo > 2σ(Fo
)
1286
115
1.120
0.0230
0.0582
0.306
no. of params
GOOF
R1
wR2
final diff map electron
density (e Å-3
)
1H-NMR ([D8]THF, 25 °C, 400 MHz): δ 0.90 (s, CH3, 6 H),
0.94 (s, CH3, 6 H), 1.48 (s, CH3, 12 H), 1.50-2.00 (m, CH2, 16
H), 4.11 (s, OH, 4 H). 13C-NMR ([D8]THF, 25 °C, 100.6 MHz):
δ 14.7 (CH3), 18.8 (CH2), 30.6 (CH3), 47.3 (CH2), 70.5 (CPr-
MeOH), 134.5 (Ct). Decomposn pt ) 119 °C.
mL of THF for 2 h. Then the solvent was removed in vacuum
and the residue was dissolved in 10 mL of diethyl ether. At
-20 °C 6 precipitated. Yield: 0.56 mmol (0.220 g); 54.8%.
Anal. Calc for C22H38O2Ni: Ni, 14.93. Found: Ni, 14.81. IR:
1815 (s, CtC), 3381 (s, OH) cm-1 1H-NMR (C6D6, 25 °C, 100
.
(Bis(1-h yd r oxycycloh exyl)eth yn e)2Ni, 4. A 1.10 mmol
(0.243 g) amount of (cdt)Ni and 2.20 mmol (0.488 g) of bis(1-
hydroxycyclohexyl)ethyne were dissolved at -40 °C in a
mixture of 75 mL of diethyl ether and 50 mL of THF. After
being warmed to room temperature, the solution was filtered.
At -30 °C the product crystallized. Afterward it was washed
twice with pentane and dried in vacuum. Yield: 0.45 mmol
(0.227 g); 41.2%. Anal. Calc for C28H44O4Ni: C, 66.90; H, 8.83;
Ni, 11.53. Found: C, 68.12; H, 8.73; Ni, 11.49. IR: 1882 (s,
MHz): δ 1.02 (m, CH3, 12 H), 1.34 (s, CH3, 6 H), 1.53 (m, CH,
2 H), 1.85-2.00 (m, CH2, 12 H), 2.84 (s, OH, 2 H), 5.28 (s,
CHd, 4 H). 13C-NMR (C6D6, 25 °C, 50.3 MHz): δ 25.0, 29.9,
30.2, 31.8 (CH3, CH2), 52.6 (CH2); δ 73.4 (C-i-BuMeOH); δ 95.1
(CHd); δ 136.0 (Ct).
(cod )Ni(3,6-d ieth yloct-4-yn e-3,6-d iol), 7. The experi-
mental procedure was carried out in a similar method to that
used for 6. Anal. Calc for C20H34O2Ni: Ni, 16.07. Found: Ni,
16.12. IR: 1808 (s, CtC), 3253 (s, OH) cm-1
.
CtC), 3237 (s, OH) cm-1
.
1H-NMR ([D8]THF, 25 °C, 200
(2-Meth yl-5,5-dim eth ylh ex-3-yn -2-ol)2Ni, 10. A 1.14 mmol
(0.251 g) amount of (cdt)Ni and 2.58 mmol (0.369 g) of
2-methyl-5,5-dimethylhex-3-yn-2-ol were dissolved at -60 °C
in 10 mL of pentane. After being warmed to room tempera-
ture, the solution was filtered and left standing at room
temperature for 4 h. The solvent was evaporated in vacuum.
MHz): δ 1.73 (m, CH2, 40 H); 4.11 (s, OH, 4 H). 13C-NMR
([D8]-THF, 25 °C, 50.3 MHz): δ 24.1 (CH2); 26.5 (CH2); 41.2
(CH2); 69.8 (CH2); 135.0 (Ct). Decomposn pt ) 141 °C.
(2,4,7,9-Tetr a m eth yld ec-5-yn e-4,7-d iol)2Ni, 5. A 2.16
mmol (0.447 g) amount of (cdt)Ni and 4.32 mmol (0.977 g) of
2,4,7,9-tetramethyldec-5-yne-4,7-diol were mixed at room tem-
perature in 60 mL of pentane. At -30 °C 5 precipitated. The
precipitate was isolated, washed twice with cold pentane (-20
°C), and dried in vacuum. Yield: 1.52 mmol (0.777 g); 70.4%.
Anal. Calc for C28H52O4Ni: C, 65.76; H, 10.25; Ni, 11.48.
Found: C, 64.02; H, 9.86; Ni, 11.63. IR: 1885 (s, CtC), 3304
IR: 1892 (s, CtC), 3331 (s, OH) cm-1
.
1H-NMR ([D8]THF, 25
°C, 200 MHz): δ 1.27 (s, CH3, 18 H), 1.45 (s, CH3, 12 H), 3.72
(s, OH, 2 H). 13C-NMR ([D8]THF, 25 °C, 50.3 MHz): δ 30.3
(CMe3), 31.3-32.5 (CH3), 67.1 (CMe2OH), 133.2 and 136.5
(Ct). Single crystals were obtained from pentane/THF (100/
1) as a byproduct of (alkyne)4Ni3. Some crystals were sepa-
rated. Anal. Calc for C18H32O2Ni: C, 63.75; H, 9.51. Found:
(s, OH) cm-1
.
1H-NMR ([D8]THF, 25 °C, 400 MHz): δ 0.96
(m, CH3, 24 H), 1.47 (s, CH3, 12 H), 1.62 (m, CH2, 8 H), 2.00
(m, CH, 4 H), 3.85 (s, OH, 4 H). 13C-NMR ([D8]THF, 25 °C,
100.6 MHz): δ 24.8 (CH3), 25.8 (CH), 31.9 (CH3), 53.1 (CH2),
70.0-71.1 (4 signals, C-i-BuMeOH), 134.8-135.2 (6 signals,
Ct). Decomposn pt ) 88 °C.
(cod)Ni(2,4,7,9-tetr am eth yldec-5-yn e-4,7-diol), 6. A 1.02
mmol (0.280 g) amount of 2,4,7,9-tetramethyldec-5-yne-4,7-
diol and 1.10 mmol (0.250 g) of (cod)2Ni were refluxed in 10
C, 63.52, H, 9.78. IR: 1892 (s, CtC), 3227 (s, OH) cm-1
.
(3-Eth yl-6,6-dim eth ylh ept-4-yn -3-ol)2Ni, 12. A 1.60 mmol
(0.353 g) amount of (cdt)Ni and 3.57 mmol (0.60 g) of 3-ethyl-
6,6-dimethylhept-4-yn-3-ol were mixed at -35 °C in 20 mL of
pentane. After reaching room temperature, the mixture was
filtered and left standing for 2 h at room temperature. The
solution was concentrated to 5 mL. At -78 °C 12 precipitated.
Single crystals were obtained from diethyl ether. Yield: 0.32

Bis(alkyne)metal(0) Complexes
Organometallics, Vol. 15, No. 9, 1996 2319
mmol (0.126 g); 20%. Anal. Calc for C22H40O2Ni: C, 66.96;
in 5 mL of diethyl ether. The solution was allowed to warm
to room temperature and was then left standing for 3 h.
Afterward it was concentrated to 2 mL. At -78 °C 11
precipitated as colorless crystals. Yield: 0.11 mmol (0.052 g),
23%. Anal. Calc for C18H32O2Pt: C, 45.45; H, 6.79. Found:
H, 10.23. Found: C, 64.96; H, 10.60. IR: 1901 (s, CtC), 3441
(s, OH) cm-1 1H-NMR (C6D6, 25°C, 200 MHz): δ 1.06 (t, CH3,
.
12 H), 1.24 (s, CH3, 18 H), 1.77 (q, CH2, 8 H). 13C-NMR (C6D6,
25 °C, 50.3 MHz): δ 9.1 (CH3), 31.3 (CMe3), 31.8 (CH3), 35.5
(CH2), 73.9 (CEt2OH), 129.8 and 138.2 (Ct).
C, 45.88; H, 6.79. IR: 1889 (s, CtC), 3325 (s, OH) cm-1 1H-
.
P la tin u m Com p ou n d s. (2,4,7,9-Tetr a m eth yld ec-5-yn e-
4,7-d iol)2P t, 8. A 0.050 mmol (0.206 g) amount of Pt(cod)2
and 1.00 mmol (0.227 g) of (2,4,7,9-tetramethyldec-5-yne-4,7-
diol) were dissolved at room temperature in 20 mL of diethyl
ether. The mixture was filtered and then concentrated to 8
mL. At -78 °C 8 precipitated. 8 was isolated, washed with
pentane, and dried in vacuum. Yield: 0.44 mmol (0.293 g);
87.4%. Anal. Calc for C28H52O4Pt: C, 51.90; H, 8.10. Found:
NMR ([D8]THF, 25 °C, 200 MHz): δ 1.28 (s, CH3, 18 H), 1.45
(s, CH3, 6 H), 1.46 (s, CH3, 6 H), 2.38 (s, OH, 2 H). 13C-NMR
(C6D6, 25 °C, 50.3 MHz): δ 29.6 (CMe3), 31.5-32.6 (CH3), 65.2
(CMe2OH), 128.6 and 131.3 (Ct).
Ack n ow led gm en t. Support of this research by the
Deutsche Forschungsgemeinschaft (Sonderforschungs-
bereich 247) and the Fond der Chemischen Industrie is
gratefully acknowledged.
C, 52.18; H, 8.30. IR: 1884 (s, CtC), 3298 (s, OH) cm-1 1H-
.
NMR ([D8]THF, 20 °C, 200 MHz): δ 0.98 (m, CH3, 24 H); δ
1.46 (s, CH3, 12 H); δ 1.62 (m, CH2, 8 H); δ 2.02 (m, CH, 4 H);
δ 3.92, 3.95, 3.98 (s, OH, 4 H). 13C-NMR ([D8]THF, 25 °C, 50.3
MHz): δ 25.0 (CH3), 25.2 (CH), 31.5-31.8 (6 signals, CH3),
52.6 and 52.7 (CH2), 69.1-69.2 (3 signals, C-i-BuCH3OH),
130.5-131.0 (6 signals, Ct).
(2,5-Dim eth ylh ex-3-yn e-2,5-d iol)2P t, 9. The experimen-
tal procedure was modified from that reported in the literature
and was carried out in a similar method to that for 11.5 Single
crystals are obtained from THF/hexane.
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, positional and thermal parameters, and bond distances
and angles (46 pages). Ordering information is given on any
current masthead page. Additional material on the X-ray
structure analyses is available from the Fachinformationszen-
trum Chemie, Physik, Mathematik GmbH, 76344 Eggenstein-
Leopoldshafen 2, Germany, by mentioning the deposit num-
bers CSD-404129 (1), 404310 (6), 404309 (7), 404130 (9),
404311 (10), 404132 (11), and 404131 (12), the author, and
the journal citation.
(2-Meth yl-5,5-dim eth ylh ex-3-yn -2-ol)2P t, 11. A 0.47 mmol
(0.193 g) amount of (cod)2Pt and 0.94 mmol (0.133 g) of
2-methyl-5,5-dimethylhex-3-yn-2-ol were mixed at -30 °C
OM950896U