Photochemical reactions of 1-ferrocenyl-4-phenyl-1,3-butadiyne with Fe(CO)5 and CO

Article abstract of DOI:10.1016/j.jorganchem.2010.05.004

Photolysis of a hexane solution containing ironpentacarbonyl, 1-ferrocenyl-4-phenyl-1,3-butadiyne at low temperature yields six new products: [Fe(CO)₂{η²:η²-PhCCCC(Fc)C(CCPh)C(Fc) Fe(CO)₃}-μ-CO] (1), [Fe₂(CO)₆{μ- η¹:η¹:η²:η²- PhCCCC(Fc)-C(O)-C(Fc)CCCPh}] (2), [Fe₂(CO)₆{μ- η¹:η¹:η²:η²-FcCC(CC Ph)-C(O)-C(Fc)CCCPh}] (3), [Fe₂(CO)₆{μ- η¹:η¹:η²:η²- FcCCCC(Fc)-C(O)-C(Fc)CCCPh}] (4), [Fe(CO)₃{μ-η²: η²-[FcCC(CCPh)C(CCPh)C(Fc)}CO] (5) and [Fe(CO) ₃{μ-η²: η²-[FcCC(CCPh)C(CCPh)C(Fc)} CO] (6) formed by coupling of acetylenic moieties with CO insertion on metal carbonyl support. In presence of CO, formation of another new product 2,5-bis(ferrocenyl)-3,6-bis(tetracarbonylphenylmaleoyliron)quinone (7) was observed which on further reaction with ferrocenylacetyene gave the quinone, 2,5-bis(ferrocenyl)-3,6-bis(ethynylphenyl)quinone (8). Structures of 1-5 and 8 were established crystallographically. Photolysis of a hexane solution containing Fe(CO)₅, FcC₂C₂Ph at low temperature yields six new products [Fe(CO)₂{η²: η²-PhCCCC(Fc)C(CCPh)C(Fc)Fe(CO)₃}-μ-CO] (1), [Fe(CO)₆{μ-η¹:η¹:η²: η²-R¹CC(R²)-C(O)-C(R³)CR ⁴ }] (2-4), [Fe(CO)₃{μ-η²: η²- [R¹CC(R²)C(R³)C(R ⁴)}CO] (5, 6). In presence of CO, 2,5-bis(ferrocenyl)-3,6- bis(tetracarbonylphenylmaleoyliron)quinone (7) forms which on reaction with FcC₂H gave the quinone, 2,5-bis(ferrocenyl)-3,6-bis(ethynylphenyl) quinone (8).

Full text of DOI:10.1016/j.jorganchem.2010.05.004

Journal of Organometallic Chemistry 695 (2010) 1986e1992
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Photochemical reactions of 1-ferrocenyl-4-phenyl-1,3-butadiyne
with Fe(CO)5 and CO
,
b
,
a
a
Pradeep Mathur a , Radhe Shyam Ji , Sathyanarayana Boodida ,
*
Amrendra K. Singh a, Shaikh M. Mobin b
a Department of Chemistry, Indian Institute of Technology e Bombay, Powai, Bombay 400 076, India
b National Single Crystal X-ray Diffraction Facility, Indian Institute of Technology e Bombay, Powai, Bombay 400 076, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Photolysis of a hexane solution containing ironpentacarbonyl, 1-ferrocenyl-4-phenyl-1,3-butadiyne at
low temperature yields six new products: [Fe(CO)2{h2
:
h
2-PhC^CCC(Fc)C(C^CPh)C(Fc)Fe(CO)3}-
m
-CO]
2-FcCC
2-FcC^CCC(Fc)eC(O)eC(Fc)CC^CPh}] (4),
2-[FcCC(C^CPh)C(C^CPh)C(Fc)}CO] (5) and [Fe(CO)3{ h2 2-[FcCC(C^CPh)C(C^CPh)
Received 20 February 2010
Received in revised form
5 May 2010
Accepted 6 May 2010
Available online 12 May 2010
(1), [Fe2(CO)6{
(C^C Ph)eC(O)eC(Fc)CC^CPh}] (3), [Fe2(CO)6{
[Fe(CO)3{
h2
m
-
h1
:
h1
:
h2
:
h
2-PhC^CCC(Fc)eC(O)eC(Fc)CC^CPh}] (2), [Fe2(CO)6{
h1 h1 h2
m- : : :h
h1 h1 h2
m
-
:
:
:h
m
-
:
h
m
-
: h
C(Fc)}CO] (6) formed by coupling of acetylenic moieties with CO insertion on metal carbonyl support. In
presence of CO, formation of another new product 2,5-bis(ferrocenyl)-3,6-bis(tetracarbonylphenylma-
leoyliron)quinone (7) was observed which on further reaction with ferrocenylacetyene gave the quinone,
Keywords:
Butadiyne
Insertion reaction
Iron carbonyl
Clusters
2,5-bis(ferrocenyl)-3,6-bis(ethynylphenyl)quinone (8). Structures of 1e5 and
8 were established
crystallographically.
Ó 2010 Elsevier B.V. All rights reserved.
Crystal structure
1. Introduction
tetranuclear clusters in which only one alkyne group coordinates
are formed [12,13]. The free alkyne of cluster can be further used for
cluster growth reactions as reported in the formation of the hex-
Reactions of ferrocenyl substituted alkynes with cluster
carbonyls are of considerable interest due to their applications like
multielectron redox catalysts [1,2] and electron storage devices [3].
Intense electronic communication observed in complexes with two
or more ferrocenyl units separated by conjugated bridging ligands
is also of much interest [4e6]. At the same time, the presence of one
or more unsaturated bonds in the molecules of diynes offers
additional features for the co-ordination to metal atoms in a cluster
and for the formation of carbonecarbon bonds.
anuclear cluster [Ru6(m5- : : : :h - : : :
h1 h1 h1 h2 2-PhCHC3C6H4)(m4 h1 h1 h2
h2ePhCHC3C6H4)(CO)15] [14]. In the present work, we report the
photochemical reactions of the unsymmetrical 1-ferrocenyl-4-
phenyl-1,3-butadiyne with Fe(CO)5 and CO at low temperature.
2. Results and discussion
2.1. Photolysis of 1-ferrocenyl-4-phenyl-1,3-butadiyne with Fe(CO)5
As part of our systematic investigation on the reactivity of the
alkynes with metal carbonyls and clusters [7e10], we have previ-
ously reported the reaction of 1,4-diferrocenyl-1,3-butadiyne with
Photolysis of a hexane solution of 1-ferrocenyl-4-phenyl-1,3-
butadiyne (FcC^CC^CPh) and Fe(CO)5 at low temperature (0 ꢀC)
yields six new compounds 1e6 resulting from the coupling of
acetylenic moieties with CO insertion on metal carbonyl framework
(Scheme 1). All new compounds were isolated by chromatographic
techniques as air stable solids. In solution, slow decomposition was
observed in air.
Ru(CO)5 to form [Ru2(CO)6{C4Fc2(C^CFc)2}2], [Ru2(CO)6[
m
-
-
h1
h1
:
:
h1
h1
:
:
h2
h2
:
:
h
h
2-{FcC^CCC(Fc)eC(O)eC(Fc)CCCFc}]] and [Ru2(CO)6[
2-{FcC^CCC(Fc)eC(O)eC(eC^CFc)C(Fc)}]]
[11].
m
When
M3(CO)10(NCMe)2 (M ¼ Os or Ru) react with diynes 1,4-dialkyl-1,3-
butadiyne (alkyl ¼ ferrocenyl, Me, Et, Ph, But, SiMe3) trinuclear or
The IR spectra of compounds 1e6 show the presence of terminal
carbonyls; whereas 1 indicates the presence of semibridging CO in
addition to the terminal carbonyls, compounds 2e6 show only
terminal carbonyls. 1H and 13C NMR spectra of 1e6 confirm the
presence of Cp rings and phenyl rings of the FcC^CC^CPh and
carbonyl groups. Crystals of 1e5, suitable for X-ray analysis, were
* Corresponding author. Department of Chemistry, Indian Institute of Technology
e Bombay, Powai, Bombay 400 076, India. Tel.: þ91 22 25767180; fax: þ91 22
25767152.
E-mail address: mathur@iitb.ac.in (P. Mathur).
0022-328X/$ e see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2010.05.004

P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 1986e1992
1987
Scheme 1. Reaction of 1-ferrocenyl-4-phenyl-1,3-butadiyne with Fe(CO)5.
grown by slow evaporation of hexane/dichloromethane solutions
and their molecular structures are shown in Figs. 1e5 respectively
(Fig. 6).
complexation, and these are also longer than the corresponding
distances of the metallocycopentadiene ring of [Fe2(CO)6(C4H2Fc2)],
[Ru2(CO)6(C4H2Fc2)], and [Ru2(CO)6{C4Fc2(C^CFc)2}] [11]. In
general, the metallacyclopentadiene ring in 1 is similar to that in
[Fe2(CO)6C4H2Fc2] [10], [Ru2(CO)6(C4H2Fc2)] [15], and [Ru2(CO)6-
{C4Fc2(C^CFc)2}2] [11], which are formed in the theromolysis
reaction of FcC^CH and Fe(CO)5, FcC^CH and Ru3(CO)12 and in the
photolysis of FcC^CC^CFc and Ru(CO)5 respectively.
The molecular structure 1 contains a ferracyclopentadiene ring
which is formed by a formal coupling of two FcC^CC^CPh mole-
cules with an Fe(CO)3 unit. Position 2 and 4 of the ring are occupied
by the bulky ferrocenyl groups whereas position 3 and 5 are taken
by {PhC^C} groups. This ferracyclopentadiene ring is
h
4-coordi-
nated to another Fe(CO)2 fragment which is also bonded to the ring
iron atom (2.498(2)) Å. A sixth carbonyl ligand bridges the metal-
emetal bond. Within the C4Fe ring, C(8)eC(27) at 1.451 Å is longer
than the corresponding CeC single bond distance of 1.415(6) in the
C4Fe ring of [Fe2(CO)6(C4H2Fc2)] and similar to that of 1.455(9) Å in
the C4Ru ring of [Ru2(CO)6{C4Fc2(C^CFc)2}] [11]. The C(7)eC(8) and
C(27)eC(28) bond distances of 1.432(7) and 1.455(7) Å, respectively
are lengthened from the normal C]C double bond distance due to
The molecular structures of isomers 2e4 consist of a diir-
onbicyclo[3.1.1]heptadienone ring. Each iron atom bears three
terminal carbonyl ligands and there is
a double bond of the ring and an iron atom. Two iron atoms of the
ring are connected through a direct bond and fulfill its electronic
requirements. In 2, the two bulky ferrocenyl groups are located in
h
2-bonding between
the b-position of the ring with respect to the metal atom and the
Fig. 2. ORTEP diagram of [Fe2(CO)6{
(2) with 50% probability ellipsoids. Selected bond lengths (Å) and bond angles (ꢀ): Fe
(1)eC(9) 1.986(7), Fe(1)eC(13) 2.053(7), Fe(1)eC(12) 2.188(7), Fe(2)eC
m- : : :h
h1 h1 h2 2-PhC^CC(Fc)eC(O)eC(Fc)CC^CPh}]
¼
¼
¼
Fig. 1. ORTEP diagram of [Fe(CO)2{h2
:
h
2-PhC^CCC(Fc)C(C^CPh)CC(Fc)Fe(CO)3}-
m-CO]
(13) ¼ 1.983(7), Fe(2)eC(8) ¼ 2.211(7), Fe(2)eC(9) ¼ 2.056(7), Fe(1)eFe(2) ¼ 2.528(1),
(1) with 50% probability ellipsoids. Selected bond lengths (Å) and bond angles (ꢀ): Fe
(1)eC(7) ¼ 2.177(5), Fe(1)eC(8) ¼ 2.139(5), Fe(1)eC(27) ¼ 2.188(5), Fe(1)eC(28) ¼ 2.10
(5), Fe(2)eC(7) ¼ 1.955(5), Fe(2)eC(28) ¼ 1.961(6), Fe(1)eFe(2) ¼ 2.498(2), C(7)eC
(8) ¼ 1.432(7), C(8)eC(27) ¼ 1.451(7), C(27)eC(28) ¼ 1.455(7), C(7)eC(17) ¼ 1.483(7),
C(9)eC(8) ¼ 1.422(10), C(8)eC(1) ¼ 1.504(9), C(1)eC(12) ¼ 1.50(1), C(12)eC(13) ¼ 1.42
(1), C(8)eC(22)
¼
1.46(1), C(9)eC(10)
¼
1.42(1), C(13)eC(14)
¼
1.44(1), C(12)eC
(38) ¼ 1.47(1), C(10)eC(11) ¼ 1.21(1), C(14)eC(15) ¼ 1.191(1), and C(1)eO(1) ¼ 1.22(8);
Fe(1)eC(13)eC(12) ¼ 75.7(4), Fe(1)eC(12)eC(13) ¼ 65.4(4), C(9)eFe(1)eC(12) ¼ 83.4
(3), C(9)eFe(1)eC(13) ¼ 88.3(3), C(9)eFe(2)eC(13) ¼ 83.3(3), C(8)eFe(2)eC(13) ¼ 83.3
(3), Fe(2)eC(8)eC(9) ¼ 64.7(4), Fe(2)eC(9)eC(8) ¼ 76.6(4), C(12)eC(13)eFe(2) ¼ 115.9
C(9)eC(8)
¼
1.436(7), C(28)eC(29)
¼
1.424(7), C(27)eC(37)
¼
1.463(8), C(29)eC
(30) ¼ 1.195(7), and C(9)eC(10) ¼ 1.192(7); Fe(2)eC(7)eC(8) ¼ 116.6(4), C(7)eC(8)eC
(27) ¼ 114.2(5), C(8)eC(27)eC(28) ¼ 110.1(5), C(27)eC(28)eFe(2) ¼ 117.5(4), O(2)eC
(2)eFe(1) ¼ 167.7(6), O(1)eC(1)eFe(1) ¼ 179.3(5), O(3)eC(3)eFe(1) ¼ 178.3(5).
(5), C(1)eC(12)eC(13)
(1) ¼ 110.7(6).
¼
111.0(6), C(8)eC(1)eC(12)
¼
114.9(6), and C(9)eC(8)eC

1988
P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 1986e1992
Fig. 3. ORTEP diagram of [Fe2(CO)6{m- : : :h
h1 h1 h2 2-PhC^CCC(Fc)eC(O)eC(Fc)
CC^CPh}] (3) with 50% probability ellipsoids. Selected bond lengths (Å) and bond
angles (ꢀ): Fe(1)eC(9) ¼ 2.062(4), Fe(1)eC(8) ¼ 2.202(4), Fe(1)eC(12) ¼ 1.994(3), Fe
Fig. 5. ORTEP diagram of [Fe(CO)3{m- : h
h2 2-[FcCC(C^CPh)C(C^CPh)C(Fc)}CO] (5)
with 50% probability ellipsoids. Selected bond lengths (Å) and bond angles (ꢀ): Fe(1)eC
(5) ¼ 2.162(4), Fe(1)eC(6) ¼ 2.097(4), Fe(1)eC(9) ¼ 2.165(4), Fe(1)eC(10) ¼ 2.081(4), C
(1)eC(5) ¼ 1.493(6), C(5)eC(6) ¼ 1.441(6), C(6)eC(10) ¼ 1.449(5), C(10)eC(9) ¼ 1.441
(2)eC(9)
¼
1.976(4), Fe(2)eC(12)
¼
2.140(4), Fe(2)eC(13)
¼
2.141(4), Fe(1)eFe
(2) ¼ 2.5318(7), C(9)eC(8) ¼ 1.425(5), C(8)eC(1) ¼ 1.502(5), C(1)eC(13) ¼ 1.512(5), C
(6), C(9)eC(1)
¼
1.479(6), C(5)eC(19)
¼
1.451(6), C(6)eC(7)
¼
1.431(6), C(10)eC
(12)eC(13) 1.432(5), C(8)eC(22) 1.484(5), C(9)eC(10) 1.439(5), C(13)eC
¼
¼
¼
(11) ¼ 1.432(6), C(9)eC(35) ¼ 1.456(6), C(7)eC(8) ¼ 1.193(5), C(11)eC(12) ¼ 1.197(6),
and C(1)eO(1) ¼ 1.226(5); Fe(1)eC(5)eC(6) ¼ 67.8(2), Fe(1)eC(6)eC(10) ¼ 69.1(2), Fe
(1)eC(10)eC(9) ¼ 73.4(3), Fe(1)eC(9)eC(10) ¼ 67.0(2), C(9)eC(1)eC(5) ¼ 105.0(4), C
(1)eC(5)eC(6) ¼ 106.7(4), C(5)eC(6)eC(10) ¼ 109.1(3), C(6)eC(10)eC(9) ¼ 107.6(4), C
(10)eC(9)eC(1) ¼ 108.3(3), C(6)eC(5)eC(19) ¼ 127.1(4), C(5)eC(6)eC(7) ¼ 127.1(4), C
(11)eC(10)eC(9) ¼ 128.7(4), C(10)eC(9)eC(35) ¼ 126.5(4), Fe(1)eC(6)eC(5) ¼ 72.6(2),
and Fe(1)eC(10)eC(6) ¼ 70.3(2).
(14) ¼ 1.438(5), C(12)eC(38) ¼ 1.469(5), C(10)eC(11) ¼ 1.192(5), C(14)eC(15) ¼ 1.195
(5), and C(1)eO(1) ¼ 1.207(4); Fe(1)eC(9)eC(8) ¼ 75.9(2), Fe(1)eC(8)eC(9) ¼ 65.2(2),
Fe(1)eC(12)eC(13) ¼ 111.7(3), Fe(2)eC(12)eC(13) ¼ 70.5(2), Fe(2)eC(13)eC(12) ¼ 70.4
(2), Fe(2)eC(9)eC(8) ¼ 116.4(3), C(10)eC(9)eC(8) ¼ 112.9(3), C(1)eC(8)eC(9) ¼ 110.3
(3), C(8)eC(1)eC(13)
¼
113.0(3), C(14)eC(13)eC(12)
¼
127.9(3), C(1)eC(13)eC
(12) ¼ 111.8(3), C(13)eC(12)eC(38) ¼ 122.2(3), and C(8)eC(9)eC(10) ¼ 122.9e(3).
two {PhC^Ce} on the a-carbon of the ring whereas in 3, the fer-
a-carbons bear the free {FcC^Ce}, {PhC^Ce} groups with respect
rocenyl and {PhC^Ce} groups occupy the alternative positions on
the Fe2C5(O) ring. Formation of diironbicycloheptadienone ring is
a consequence of a formal 2 þ 2 þ 1 þ1 coupling of two FcC4Ph, one
CO molecule and one Fe2(CO)6 unit. In 2 and 3, triple bonds adja-
cent to bulky ferrocenyl group get coupled in contrast to 4, in which
alternative triple bonds couple to form Fe2C5(O) ring and the
to metal atoms. The bond parameters of the diironbicyclo-
heptadienone rings of 2, 3, and 4 are similar. As in the structure of 1,
in 2, 3, and 4 also, lengthening of the complexed CeC bonds [C(8)e
C(9) ¼ 1.42(1) Å; C(12)eC(13) ¼ 1.42(1) Å in 2, C(8)eC(9) ¼ 1.43
(5) Å; C(12)eC(13) ¼ 1.43(5) Å in 3, and C(8)eC(9) ¼ 1.42(10) Å; C
(13)eC(14) ¼ 1.41(1) Å] in 4, as compared to the complexed C]C
bonds is observed. This is consistent with observations previously
made for diruthenabicycloheptadienone ring and for
h
4-cyclo-
pentadienone complexes [16e19]. The unbridged FeeFe bonds in 2,
3, and 4 (2.528(1), 2.532(7), and 2.536(2) Å, respectively) are longer
than the CO bridged FeeFe bond of 1(2.498(2) Å).
Fig. 4. ORTEP diagram of [Fe2(CO)6{m- : : :h
h1 h1 h2 2-FcC^CCC(Fc)eC(O)eC(Fc)
CC^CPh}] (4) with 50% probability ellipsoids. Selected bond lengths (Å) and bond
angles (ꢀ): Fe(1)eC(9) ¼ 1.993(7), Fe(1)eC(14) ¼ 2.070(7), Fe(1)eC(13) ¼ 2.203(7), Fe
(2)eC(14)
¼
1.983(8), Fe(2)eC(9)
¼
2.099(7), Fe(2)eC(8)
¼
2.169(7), Fe(1)eFe
(2) ¼ 2.5364(17), C(9)eC(8) ¼ 1.416(10), C(8)eC(1) ¼ 1.498(10), C(1)eC(13) ¼ 1.511
(10), C(13)eC(14) ¼ 1.411(10), C(9)eC(10) ¼ 1.44(1), C(8)eC(18) ¼ 1.49(1), C(13)eC
(39) ¼ 1.47(1), C(14)eC(15) ¼ 1.42(1), C(15)eC(16) ¼ 1.209(9), C(10)eC(11) ¼ 1.18(1),
and C(1)eO(1) ¼ 1.199(8); Fe(1)eC(9)eC(8) ¼ 115.6(5), Fe(1)eC(13)eC(14) ¼ 65.7(4),
Fe(1)eC(14)eC(13) ¼ 75.9(4), Fe(2)eC(14)eC(13) ¼ 114.5(5), Fe(2)eC(8)eC(9) ¼ 68.0
(4), Fe(2)eC(9)eC(8) ¼ 73.3(4), C(9)eC(8)eC(1) ¼ 109.8(6), C(1)eC(13)eC(14) ¼ 112.2
Fig. 6. ORTEP diagram of 2,4-diferrocenyl-3,6-bis(phenylethynyl) cyclohexa-2,5-
diene-1,4-dione (8) with 50% probability ellipsoids. Selected bond lengths (Å) and
bond angles (ꢀ): C(3)eC(4) ¼ 1.362(8), C(5)eC(6) ¼ 1.195(9), C(7)eC(8) ¼ 1.361(8), C
(7), C(8)eC(1)eC(13)
¼
114.1(6), C(13)eC(14)eC(15)
¼
125.5(7), C(14)eC(13)eC
(10)eC(9)
¼
1.194(8), C(1)eO(1)
¼
1.238(7), C(2)eO(2)
¼
1.212(7); C(3)eC(4)eC
(39) ¼ 125.2(6), C(9)eC(8)eC(18) ¼ 128.4(7), and C(8)eC(9)eC(10) ¼ 125.9(3).
(5) ¼ 123.5(6) and C(7)eC(8)eC(9) ¼ 124.0(6).

P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 1986e1992
1989
Scheme 2. Reaction of 1-ferrocenyl-4-phenyl-1,3-butadiyne with Fe(CO)5 and CO.
The molecular structure of 5 consists of an Fe(CO)3 unit
coordinated to cyclopentadienone ring with a Fe(CO)3 unit h4
bonded to it, formally resulting from a 2 þ 2 þ 1 coupling of two
FcC4Ph molecules with one CO molecule. In contrast to 1, the
carbonyl group. 1H and 13C NMR spectra of compound 7 confirm the
presence of Cp rings, phenyl rings of FcC^CC^CPh and carbonyl
groups. Mass spectrum of compound 7 shows a peak centered at
m/z 1096, for [MeCO]. All attempts to grow suitable crystal for
single-crystal X-ray structure determination were unsuccessful.
However, based on the spectroscopic data 7, can be identified as
a biferrole derivative of quinone. To substantiate this, its reaction
with ferrocenylacetylene was investigated. The reaction yields the
quinone 8 and compound 9 (Scheme 3). Compound 8 was identi-
fied crystallographically (Fig. 6). When compound 9 was photo-
lyzed with ferrocenyleneacetylene compounds 10 and 11 were
obtained and this reaction is similar to that of FcCCH and Fe(CO)5
reported earlier (Scheme 4) [20].
ferrocenyl groups attached to the cyclopentadienone ring at
carbons and are “syn”, opposite to the Fe(CO)3 unit. The two free
{PhC^Ce} groups are located at the -positions of the ring with
a-
b
respect to ring CO. The cyclopentadineone ring is not planar, and
the ]CO group is out of the plane with an angle of e15ꢀ in
cyclopentadienone ring [10]. The bond distances C(5)eC(6) (1.44
(2) Å), C(6)eC(10) (1.45(5) Å), and C(9)eC(10) (1.44(2) Å) are
indicative of delocalization of 4ꢁ
p electrons over these four
carbon atoms.
Based on the similarity in the spectroscopic data of 6 with that of
5, molecular structure for compound 6 can be proposed as
a
In this paper we have reported the low temperature photo-
chemical reaction of Fe(CO)5 and FcC^CC^CPh. Photolysis of
FcC^CC^CPh and Fe(CO)5 yields a mixture of ferracyclopenta-
cyclopentadienone ring derivative [Fe(CO)3{m- : h
h2 2-[FcCC
(C^CPh)C(C^CPh)C(Fc)}CO] which is an isomer of compound 5.
diene complex [Fe(CO)2{h2
(CO)3}-
heptadienone complex, [Fe2(CO)6{
(O)eC(Fc)CC^CPh}] (2), [Fe2(CO)6{
(O)eC(Fc)CC^CPh}] (3), [Fe2(CO)6{
(O)eC(Fc)CC^CPh}] (4), and two of three possible isomers of
cyclopentadienone complex, [Fe(CO)3{
h2 2-[FcCC(C^CPh)C
(C^CPh)C(Fc)}CO] (5), [Fe(CO)3{
h2 2-[FcCC(C^CPh)C(Fc)C
:h
2-PhC^CCC(Fc)C(C^CPh)CC(Fc)Fe
m
-CO] (1), three of ten possible isomers of the diferracyclo-
h1 h1 h2 2-PhC^CC(Fc)eC
h1 h1 h2 2-PhC^CCC(Fc)eC
h1 h1 h2 2-FcC^CCC(Fc)eC
m
-
-
:
:
:h
:h
:h
2.2. Photolysis of 1-ferrocenyl-4-phenyl-1,3-butadiyne with Fe
(CO)5 and CO
m
:
:
:
:
m-
In order to isolate other possible isomers, the photolytic reaction
of 1-ferrocenyl 4-phenyl 1,3-butadiyne with Fe(CO)5 and CO was
carried at low temperature. A new green compound 7 was obtained
along with compounds 1e4 (Scheme 2).
m-
: h
m-
: h
(C^CPh)}CO] (6). Compounds 1e6 have been structurally charac-
terized. It is observed that between the FcC^Ce and the PhC^Ce
units, it is the former which involves in the addition to form the
The IR spectrum of compound 7 shows the presence of terminal
carbonyls and peak at 1670 cmꢁ1 indicates the presence of aliphatic
Scheme 3. Formation of the quinone 8 and the ferrole 9.

1990
P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 1986e1992
Scheme 4. Conversion of the ferrole 9 to the quinones 10 and 11.
Fe2C5(O) rings. The PhC^Ce unit remains pendent, either in the
or -position with respect to the Fe atom.
a
-
(PhC^CCFe), 123.52e130.87 (phenylcarbons), 152.85 (FcCC(O)),
192.79, 198.63, 207.01, 208.99 (FeeCO). MS (m/z, ESþ): 929, 928. M.
P. 181e183 ꢀC
b
3: Yield: 16 mg (13%). IR (cmꢁ1, vCO): 2074 (w), 2049 (s, br), 2017
3. Experimental Section
(s, br), 1681 (br). 1H NMR (CDCl3):
d
7.41e7.46 (m, 6H, C6H5),
7.60e7.66 (m, 4H, C6H5), 4.23e4.36 (m, 13H,
5-C5H5, 5-C5H4),
4.56e4.71 (m, 2H,
5-C5H4), 5.13e5.3 (m, 3H, 5-C5H4). 13C NMR
(CDCl3): 65.84e84.24 (sub Cp carbons), 69.01e75.96 (unsub Cp
h
h
3.1. General procedure
h
h
d
All reactions and manipulations were performed using standard
Schlenk line techniques under an inert atmosphere of prepurified
argon or nitrogen. Solvents were purified, dried, and distilled under
an argon atmosphere prior to use. Infrared spectra were recorded
on a Nicolet 380 FT-IR spectrometer as hexane solutions in 0.1 mm
path length NaCl cells and NMR spectra on a Varian VXRO-300S
spectrometer in CDCl3. Iron pentacarbonyl and ferrocene were
purchased from Fluka and Spectrochem, respectively, and these
were used without further purification. Phenylacetylene was
purchased from Aldrich and used without further purification. TLC
plates were purchased from Merck (20 ꢂ 20 cm silica gel 60 F254).
Photochemical reactions were carried out using double-walled
quartz vessels and a 125 W immersion type mercury lamp oper-
ating at 366 nm, manufactured by Applied Photophysics Ltd.
FcC^CH [21] and FcC^CeC^CPh [22] were prepared following
reported procedures.
carbon), 90.75 (PhC]CC), 93.76 (PhC]CC), 112.83 (PhC]CCFe),
97.40 (FcC]CC), 98.58 (PhC]CCC(O)), 123.53e131.66 (phenyl
carbons),152.62 (FcCC(O)), 194.51, 195.13, 206.46 (FeeCO). MS (m/z,
ESþ): 929, 928, 340. M. P. 145e147 ꢀC.
4: Yield: 15 mg (13%). IR (cmꢁ1, vCO): 2180 (br), 2074 (w), 2051
(s), 2020(s) 1683 (br). 1H NMR (CDCl3):
d
7.36e7.64 (m, 10H, C6H5),
4.09e4.22(m, 18H,
h
5-C5H5,
h
5-C5H4). 13C NMR (CDCl3):
d
64.48e71.
64 (unsub Cp carbons), 83.6e84.06 (sub Cp carbons), 96.29 (PhC]
CC), 97.99 (PhC]CC), 98.06 (PhC]CC), 113.87 (PhC]CCFe), 118.02
(FcC]CCFe), 123.66e138.24 (phenyl carbons), 152.62 (FcCC(O)),
165.25 (PhCC(O)), 195.56, 209.06, 214.21 (FeeCO). MS (m/z, ESþ):
929, 928, 356. M. P. 171e172 ꢀC.
5: Yield: 2 mg (2%). IR (cmꢁ1, vCO): 2063 (s, br), 2011(s, br), 1674
(br). 1H NMR (CDCl3):
d 7.47e7.49 (m, 6H, C6H5), 7.71e7.44 (m, 6H,
C6H5), 4.21e4.44 (m, 18H,
h
5-C5H5,
h
5-C5H4). MS (m/z, ESþ): 790,
789, 788. M. P. 169e172 ꢀC.
6: Yield: 16 mg (16%). IR (cmꢁ1, vCO): 2066 (s), 2012 (s, br), 1673
(br). 1H NMR (CDCl3):
7.78e7.81 (m, 2H, C6H5), 7.65e7.67 (m, 2H,
C6H5), 7.54e7.56 (m, 3H, C6H5), 7.39e7.45 (m, 3H, C6H5), 5.52e5.58
(m, 2H,
5-C5H4), 5.27e5.29 (m, 2H, 5-C5H4), 4.40e4.56 (m, 4H, h5
C5H4), 4.16e4.27 (m, 10H, 66.85e75.
5-C5H5). 13C NMR (CDCl3):
3.2. Photolysis of Fe(CO)5 with 1-ferrocenyl-4-phenyl-1,3-
butadiyne
d
h
h
-
1-ferrocenyl-4-phenyl-1,3-butadiyne (105 mg, 0.34 mmol) and
ironpentacarbonyl (0.3 ml, 22.2 mmol) was added to the hexane
solution (60 ml) and photolyzed for 35 min at 0 ꢀC under argon
atmosphere. The solvent was removed in vacuo, the residue was
dissolved in dichloromethane and subjected to chromatographic
work-up using TLC plates. Elution with a dichloromethane/hexane
h
d
97 (sub Cp carbons), 69.63 (unsub Cp carbons), 128.69e131.97
(phenyl carbons), 97.03 (PhC]CC), 98.19 (PhC]CC), 123.11 (PhC]
CC),167.25 (CO), 207.01 (FeeCO). MS (m/z, ESþ): 790, 789, 788. M. P.
176e178 ꢀC.
mixture (35:65 v/v) gave the orange red compound [Fe(CO)2{h2
PhC^CCC(Fc)C(C^CPh)CC(Fc)Fe(CO)3}- -CO] (1), Pink compound
[Fe2(CO)6{
h1 h1 h2 2-PhC^CC(Fc)eC(O)eC(Fc)CC^CPh}] (2),
Grey compound [Fe2(CO)6{
h1 h1 h2 2-PhC^CCC(Fc)eC(O)eC
(Fc)CC^CPh}] (3), Blackish grey compound [Fe2(CO)6{
h1 h1 h2
2-FcC^CCC(Fc)eC(O)eC(Fc)CC^CPh}] (4), Pink [Fe(CO)3{ h2 h2
[FcCC(C^CPh)C(C^CPh)C(Fc)}CO] (5) and maroon compound [Fe
(CO)3{
h2 2-[FcCC(C^CPh)C(Fc)C(C^CPh)}CO] (6)
1: Yield: 21 mg (18%). IR (cmꢁ1, vCO): 2066 (s), 2036 (vs), 2001 (s,
br). 1H NMR (CDCl3):
7.36e7.63 (m, 10H, C6H5), 3.98e4.29 (m, 18H,
5-C5H5, 5-C5H4). 13C NMR (CDCl3):
68.65e73.93 (sub Cp
: -
h2
m
3.3. Photolysis of Fe(CO)5 with CO and 1-ferrocenyl-4-phenyl-1,3-
butadiyne
m-
:
:
:h
m-
:
:
:h
m
-
:
:
:
-
1-ferrocenyl-4-phenyl-1,3-butadiyne (105 mg, 0.34 mmol) and
ironpentacarbonyl (0.3 ml, 22.2 mmol) was added to the hexane
solution (60 ml) and photolyzed for 35 min at 0 ꢀC under contin-
uous bubbling of CO. The solvent was removed in vacuo, the residue
was subjected to chromatographic work-up using TLC plates.
Elution with a dichloromethane/hexane mixture (35:65 v/v) gave
a green band 7 along with the compounds 1e4. The green
h
m-
:
m-
:h
d
h
h
d
carbons), 69.07 (unsub Cp carbon), 95.03 (PhC^CC), 97.91
(PhC^CC), 135.18 (PhC^CCFe), 127.55e131.73 (phenylcarbons),
211.81, 212.17 (FeeCO). MS (m/z, ESþ): 901, 900, 816, 765. M. P.
120e122 ꢀC
compound 7 was again photolyzed with ferrocenylacetylene
(21 mg, 0.1 mmol) and hexane at 0 ꢀC for 30 min under constant CO
bubbling. The solvent was removed in vacuo, the residue was dis-
solved in dichloromethane and subjected to chromatographic
work-up using TLC plates. Elution with a dichloromethane/hexane
mixture (30:70 v/v) gave the olive green compound 2,5-diferro-
cenyl-3,6-bis(phenylethynyl)cyclohexa-2,5-diene-1,4-dione (8).
7: Yield: 21 mg (20%). IR (cmꢁ1, vCO): 2109 (b), 2052 (s, br), 2028
2: Yield: 18 mg (15%). IR (cmꢁ1, vCO): 2074 (w), 2049 (vs), 2018 (s,
br), 1650 (br). 1H NMR (CDCl3):
d
7.42e7.46 (m, 6H, C6H5), 7.57e7.59
(m, 4H, C6H5), 4.22e4.37 (m, 14H,
5-C5H5, 5-C5H4), 5.06e5.07 (m,
4H, 66.01e84.51 (sub Cp carbons),
5-C5H4). 13C NMR (CDCl3):
70.09 (unsub Cp carbon), 98.28 (PhC^CC), 99.38 (PhC^CC), 113.44
h
h
h
d
(s), 1670 (b); 1H NMR (CDCl3): 5-C5H5), 4.67 (m, 4 H,
d 4.19 (s, 10 H, h

P. Mathur et al. / Journal of Organometallic Chemistry 695 (2010) 1986e1992
1991
Table 1
Crystal Data and Structure Refinement Parameters for 1e5 and 8.
1
2
3
4
5
8
Formula
Mol. wt
Temp, K
Cryst syst
Space group
a, Å
C46H28Fe4O6
900.08
150(2)
Triclinic
ꢀ
Pı
10.876(4)
13.044(4)
15.098(5)
104.24(3)
97.17(3)
113.61(3)
1841.2(10)
2
1.624
C47H28Fe4O6
928.11
150(2)
Monoclinic
P21/c
13.6121(11)
17.568(3)
16.480(16)
90
10.3166(9)
90
3837.5(8)
4
1.606
1.537
C47H28Fe4O6
928.09
150(2)
Monoclinic
P21/n
13.9695(14)
10.376(2)
27.919(3)
90
98.576(9)
90
4001.5(10)
4
1.541
1.474
C47H28Fe4O6
928.09
150(2)
Triclinic
ꢀ
Pı
11.800(3)
12.338(3)
15.350(3)
68.12(2)
68.34(2)
85.88(2)
1921.9(8)
2
1.604
1.534
940
C44H28Fe3O4
788.21
150(2)
Monoclinic
P21/c
13.6811(16)
10.5966(13)
23.370(4)
90
94.029(14)
90
3379.7(8)
4
1.549
1.317
C42H28Fe2O2
676.34
120(2)
Orthorhombic
P 21 21 21
10.1208(18)
12.0741(16)
24.888(5)
90
90
90
3041.3(9)
4
1.477
b, Å
c, Å
a
b
g
, deg
, deg
, deg
V, Å3
Z
D (calcd), Mg/mꢁ3
Abs coeff, mmꢁ1
F (000)
1.597
912
0.992
1392
1880
1880
1608
Cryst size, mm
0.27 ꢂ 0.23 ꢂ 0.18
3.11e25.00
ꢁ12 ꢃ h ꢄ 12
ꢁ15 ꢃ k ꢄ 15
ꢁ17 ꢃ l ꢄ 17
13921/6394
[R(int) ¼ 0.0821
6394/0/505
0.868
0.80 ꢂ 0.23 ꢂ 0.18
3.07e25.00
ꢁ16 ꢃ h ꢄ 16
ꢁ20 ꢃ k ꢄ 20
ꢁ19 ꢃ l ꢄ 19
28427/6738
[R(int) ¼ 0.0580
6738/0/542
1.353
0.23 ꢂ 0.18 ꢂ 0.15
2.95e25.00
ꢁ13 ꢃ h ꢄ 16
ꢁ12 ꢃ k ꢄ 12
ꢁ33 ꢃ l ꢄ 30
18977/7029
[R(int) ¼ 0.0562
7029/0/523
0.983
0.34 ꢂ 0.28 ꢂ 0.22
2.95e25.00
ꢁ14 ꢃ h ꢄ 13
ꢁ14 ꢃ k ꢄ 14
ꢁ18 ꢃ l ꢄ 18
15854/6727
[R(int) ¼ 0.1021
6727/0/523
0.98
0.33 ꢂ 0.26 ꢂ 0.21
2.93e25.00
ꢁ16 ꢃ h ꢄ 16
ꢁ12 ꢃ k ꢄ 12
ꢁ27 ꢃ l ꢄ 27
28798/5940
[R(int) ¼ 0.1137
5940/0/460
0.917
0.23 ꢂ 0.18 ꢂ 0.13
q
range, deg
2.98e25.00
Index ranges
ꢁ12 ꢃ h ꢄ 12
ꢁ14 ꢃ k ꢄ 14
ꢁ29 ꢃ l ꢄ 29
24227/5333
No. of rflns collected/unique
[R(int) ¼ 0.1849]
No. of data/restraints/param.
5333/0/415
Goodness-of-fit on F2
0.918
final R indices ([I > 2
s
(I)])
R1 ¼ 0.0544
wR2 ¼ 0.0900
R1 ¼ 0.1289
wR2 ¼ 0.1063
0.69 and ꢁ0.406
R1 ¼ 0.0788
wR2 ¼ 0.1616
R1 ¼ 0.0945
wR2 ¼ 0.1658
0.64 and ꢁ0.572
R1 ¼ 0.0393
wR2 ¼ 0.0803
R1 ¼ 0.0744
wR2 ¼ 0.0957
0.395 and ꢁ0.398
R1 ¼ 0.0663
wR2 ¼ 0.15
R1 ¼ 0.1369
wR2 ¼ 0.1759
0.895 and ꢁ0.692
R1 ¼ 0.0436
wR2 ¼ 0.0850
R1 ¼ 0.940
wR2 ¼ 0.1029
0.647 and ꢁ0.722
R1 ¼ 0.0640
wR2 ¼ 0.1053
R1 ¼ 0.1037
wR2 ¼ 0.1172
0.547 and ꢁ0.397
R indices (all data)
Largest diff peak and hole, eÅꢁ3
h
5-C5H4), 5.41e5.42 (m, 4H,
h
5-C5H4), 7.40e7.42 (m, 6H, C6H5),
128.83e131.76 (phenyl
70.59e84.95 (sub Cp carbons), 71.27 (unsub Cp
123.05 (PhC]C-), 111.75 (PhC]C-), 147. 93 (FcC]
171.85 (CO) MS (m/z, ESþ):
Acknowledgements
7.61e7.64 (m 4H, C6H5),13C NMR (CDCl3):
d
carbons),
carbons),
Ce),
d
d
P. M. is thankful to Department of Science and Technology, New
Delhi for financial support to carry out this project. R. S. J. gratefully
acknowledges the Council of Scientific and Industrial Research,
New Delhi for research fellowship.
d
d
d
d 198.93, 199.11, 202.35 (FeeCO), d
1096 [MeCO], M. P. 135e137 ꢀC.
8: Yield: 4.5 mg (21%). IR (cmꢁ1, vCO): 1658 (s, br), 1H NMR
(CDCl3): 7.65e7.68 (m, 4H, C6H5), 7.40e7.42 (m, 4H, C6H5),
5.49e5.48 (m, 2H, C6H5), 4.24 (s, 10H,
5-C5H5, 5-C5H5), 4.75e5.49
(m, 8H, 128.79e131.89
5-C5H5, 5-C5H4). 13C NMR (CDCl3):
(phenyl carbons), 56.80e73.05 (sub Cp carbons), 69.12 (unsub
Cp carbons), 107.97 (PhC]C-), 104.72 (PhC]Ce), 180.03
(FcC]C), 153.79 (FcC]C),
177.51 (CO) MS (m/z, ESþ): 676, M. P.
163e165 ꢀC.
d
Appendix A. Supplementary material
h
h
h
h
d
d
Crystallographic data for the structural analysis have been
deposited with the Cambridge Crystallographic Data Centre, CCDC
no. 732846, 732845, 732848, 732849, 732847 and 764199 for
compound 1e5 and 8. Copies of this information may be obtained
free of charge from The Director, CCDC, 12 Union Road, Cambridge
CB2 1EZ, UK (Fax: þ44 1223 336033; E-mail: deposit@ccdc.cam.ac.
uk or http://www.ccdc.cam.ac.uk).
d
d
d
d
d
d
3.4. Crystal structure determination of compounds 1e5 and 8
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measurements are given in Table 1. X-ray crystallographic data were
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