Azo-phosphine containing complexes of Group 6 metal carbonyls: Crystal and molecular structure of [Mo(CO)5{1-(4-ethylphenylazo)-6-diphenylphosphino-naphthalen-2-ol}]

Article abstract of DOI:10.1016/S0022-328X(98)00821-3

Treatment of the compounds [M(CO)₅(NCMe)] (M=Cr, Mo, W) with the phenylazonaphthylphosphines 4-R-PhN₂-1-C₁₀H₅-2-OR′-6-PPh₂ {R′=H, R=H (I), R=Me (II), R=Et (III), R=Prⁱ (IV) R=Bu^t (V); R′=C(O)Me, R=Me (VI)} afforded the mono-substituted products [M(CO)₅(L)] (1-8) (M=Cr, L=II, 1; M=Mo, L=I-VI, 2-7; M=W, L=II, 8). Further reaction of cis-[Mo(CO)₄(piperidine)₂] with the azo-phosphines I-V afforded the di-substituted complexes cis-[Mo(CO)₄(L)₂] (9-13); whereas, reaction with VI afforded cis-[Mo(CO)₄(II)₂] 10 rather than the expected compound cis-[Mo(CO)₄(VI)₂] (14). 14 can, however, be prepared by esterification of 10. The observed non-innocence of piperidene on displacement from cis-[Mo(CO)₄(piperidine)₂] has been further investigated. Thus, treatment of 7 with piperidene yielded 3 as a result it becomes apparent that the potential reactivity of the displaced ligand needs to be considered carefully when carrying out simple substitution reactions. The molecular structure of 4 is also reported.

Full text of DOI:10.1016/S0022-328X(98)00821-3

Journal of Organometallic Chemistry 568 (1998) 279–285
Azo-phosphine containing complexes of Group 6 metal carbonyls:
crystal and molecular structure of
[Mo(CO)5{1-(4-ethylphenylazo)-6-diphenylphosphino-naphthalen-2-ol}]1
Mark J. Alder, Wendy I. Cross, Kevin R. Flower *, Robin G. Pritchard
Department of Chemistry, UMIST, PO Box 88, Manchester, M60 1QD, UK
Received 8 June 1998; received in revised form 29 June 1998
Abstract
Treatment of the compounds [M(CO)5(NCMe)] (M=Cr, Mo, W) with the phenylazonaphthylphosphines 4-R–PhN2-1-C10H5-
2-OR%-6-PPh2 {R%=H, R=H (I), R=Me (II), R=Et (III), R=Pri (IV) R=But (V); R%=C(O)Me, R=Me (VI)} afforded the
mono-substituted products [M(CO)5(L)] (1-8) (M=Cr, L=II, 1; M=Mo, L=I–VI, 2–7; M=W, L=II, 8). Further reaction
of cis-[Mo(CO)4(piperidine)2] with the azo-phosphines I–V afforded the di-substituted complexes cis-[Mo(CO)4(L)2] (9–13);
whereas, reaction with VI afforded cis-[Mo(CO)4(II)2] 10 rather than the expected compound cis-[Mo(CO)4(VI)2] (14). 14 can,
however, be prepared by esterification of 10. The observed non-innocence of piperidene on displacement from cis-
[Mo(CO)4(piperidine)2] has been further investigated. Thus, treatment of 7 with piperidene yielded 3 as a result it becomes
apparent that the potential reactivity of the displaced ligand needs to be considered carefully when carrying out simple
substitution reactions. The molecular structure of 4 is also reported. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Azo-phosphines; Chromium; Molybdenum; Tungsten
1. Introduction
[M(CO)3(NCMe)3] [5], as these compounds tend to give
better yields of purer products than simple thermolysis
of the metal hexacarbonyl in the presence of the ligand
at high temperature alone. Recent examples where sim-
ple substitution reactions have occurred include: the
preparation of [M(CO)5(p1-P–P)] (P–P=dppe, dppp,
dppb) leading to the preparation of the heterobimetallic
complexes [(CO)5M(v-P–P)M%(CO)5] (M, M%=Cr,
We recently reported the synthesis of some azo-func-
tionalised phosphines by hydroxyl activated C–N cou-
pling between
a diazonium salt and a hydroxy
functionalised phosphine. [1] Having prepared these
compounds we decided to investigate their coordination
chemistry and have prepared a series of complexes
derived from Group 6 metal carbonyls. Generally, in
attempts to carry out carbonyl substitution reactions in
Group 6 metal carbonyls with phosphine based ligands
to get the reaction proceed smoothly it is often com-
mon to prepare either [M(CO)5(THF)] [2],
Mo,
W,
M"M)
[3];
reaction
between
[M(CO)5(NCMe)]
[3],
[M(CO)4(pip)2]
[4]
or
* Corresponding author. Tel.: +44 161 2004538; e-mail;
k.r.flower@umist.ac.uk
1 Paper dedicated to Professor W.R. Roper FRS on the occassion
of his 60th birthday.
Fig. 1. Compounds I–VII.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00821-3

280
M.J. Alder et al. / Journal of Organometallic Chemistry 568 (1998) 279–285
Table 1
Physical and analytical data for complexes 1–14a
Complex
Colour
Yield (%)
C (%)
H (%)
N (%)
1
2
3
4
5
6
7
8
Red
Red
Red
Red
Red
Red
Red
Red
Red
Red
Red
Red
Red
Red
47
72
34
50
31
32
60
30
54
42
75
56
57
54
57.7 (58.1)
59.3 (59.2)
59.7 (59.8)
60.1 (60.4)
61.0 (60.9)
62.1 (61.3)
59.4 (60.0)
52.9 (53.0)
66.2 (62.5)
67.8 (67.8)
63.4 (63.8)
67.4 (67.6)
64.7 (67.7)
59.8 (60.0)
4.0 (3.5)
2.6 (3.1)
3.3 (3.4)
3.4 (3.6)
4.0 (3.8)
4.6 (4.0)
3.8 (3.5)
3.0 (3.0)
4.1 (3.9)
4.4 (4.2)
4.1 (4.2)
4.7 (4.7)
4.7 (4.9)
3.8 (3.5)
3.4 (3.8)
4.2 (4.2)
4.0 (4.1)
4.1 (4.0)
3.6 (3.9)
3.7 (3.9)
3.9 (3.9)
3.5 (3.6)
5.1 (4.9)
5.3 (5.1)
4.2 (4.6)
4.6 (4.8)
4.6 (4.6)
3.9 (3.9)
9
10
11
12
13
14
a Calculated values in parentheses.
[Cp2Rh2(CO){p1-Ph2P(CH2)nPPh2}(v-p1:p1-CF3C2CF3)]
(n=1–4) and [Cr(CO)5(THF)] afforded the trimetal-
lic species [Cp2Rh2(CO)(v-p1:p1-CF3C2CF3){v-Ph2P
(CH2)nPPh2}Cr(CO)5] [6]; the water soluble compounds
[W(CO)4(L)2] (L=3-NaO2CC5H4N, 4-NaO2CC5H4N,
3,4-(NaO2C)2C5H4N, 3,5-(NaO2C)2C5H4N, 3-NaO3SC5
H4N) were prepared by displacement of piperidine from
[W(CO)4(pip)2] [7]; and a series of multimetallic species
based upon complexation of the non-coordinated phos-
phorus in [WI2(CO){p2-Ph2P(CH2)2PPh(CH2)2PPh2}
(p2-RC2R)] with [M(CO)5(NCMe)] (M=Cr, Mo, W),
[M(CO)4(pip)2] (M=Mo, W) and [Mo(CO)3(NCMe)3].
[8] Herein, we report the reactions between the azo-
phosphines 4-R–PhN2-1-C10H5-2-OR%-6-PPh2 (R%=H,
R=H (I), R=Me (II), R=Et (III), R=Pri (IV) R=
But (V); R%=C(O)Me, R=Me (VI)) and the metal
carbonyl compounds [M(CO)5(NCMe)] (M=Cr, Mo,
W) and [Mo(CO)4(pip)2] yielded the compounds
[M(CO)5(L)] (1–8) (M=Cr, L=II, 1; M=Mo, L=I–
VI, 2–7; M=W, L=II, 8) and the di-substituted
complexes cis-[Mo(CO)4(L)2] (9–13). Furthermore, we
report that on displacement of piperidine from cis-
[Mo(CO)4(pip)2] by VI affords 10 by a de-esterification
process facilitated by the piperidene.
The infrared spectra of compounds 1–8 (Table 2) all
show the expected three carbonyl stretching bands for
localised C4v· [9].
1
The H-NMR spectra, Table 3, all show the expected
resonances for the phosphines which are little peturbed
on complexation. The 31P-NMR spectra for 1–7 all
show a singlet resonance shifted downfield from the
free phosphine; 8 shows a singlet resonance straddled
1
by the expected tungsten satellites, JW-P=242 Hz.
In an attempt to prepare a series of bisphosphine
complexes the compound [Mo(CO)4(pip)2] was pre-
pared and treated with I–V affording the expected
di-substituted compounds [Mo(CO)4(L)2] 9–13 in good
yield. All of the compounds have been characterised by
elemental analysis 1H-, 31P{1H}-NMR and infrared
spectroscopy (Tables 1–3).
The infrared spectra (Table 2) all display three strong
carbonyl bands rather than the expected four where a
Table 2
Infrared data for complexes 1–14a
Complex w(CO) (cm−1
)
w(CꢀO) (cm−1
)
1
2
3
4
5
6
7
8
2065(s), 1982(w), 1930(brs)
2080(s), 1995(w), 1940(brs)
2078(s), 1990(sh), 1948(brs)
2079(s), 1989(w), 1945(brs)
2078(s), 1988(w), 1950(brs)
2079(s), 1990(w), 1948(brs)
2080(s), 1995(w), 1935(brs)
2079(s), 1985(w), 1942(brs)
2023(s), 1920(brs), 1880(brs)
2022(s), 1915(brs), 1871(brs)
2021(s), 1920(brs), 1870(brs)
2021(s), 1920(brs), 1876(brs)
2022(s), 1930(brs), 1870(brs)
2025(s), 1921(brs), 11876(brs)
2. Results and discussion
1750(m)
1745(s)
The compounds I–VI, Fig. 1, react with
[M(CO)5(NCMe)] to yield the mono-substituted prod-
ucts [M(CO)5(L)] 1–8 in good yield. All new com-
pounds have been characterised by elemental analysis,
1H-, 31P{1H}-NMR and infrared spectroscopy (Tables
1–3). Compound 4 was further characterised by a
single crystal X-ray diffraction study (Tables 4–8; see
later for structure discussion).
9
10
11
12
13
14
s, Strong; m, medium; sh, shoulder; br, broad.
a Spectra recorded as KBr discs.

M.J. Alder et al. / Journal of Organometallic Chemistry 568 (1998) 279–285
281
Table 3
Protona and 31P-NMR datab (d) for complexes 1–14
Complex 31P (l) ppm 1H (l) ppm
1
56.3
16.1 (s, 1H, OH); 8.7 (d, 1H, JHH 8.8, Ar–H); 7.8–7.3 (m, 17H, Ar–H); 7.0 (d, 1H, JHH 9.4, Ar–H); 2.4 (s,
3H, CH3)
2
3
38.1
38.1
16.1 (s, 1H, OH); 8.7 (d, 1H, JHH 8.7, Ar–H); 7.8–7.3 (m, 18H, Ar–H); 7.0 (d, 1H, JHH 9.7, Ar–H).
16.1 (s, 1H, OH); 8.7 (d, 1H, JHH 6.9, Ar–H); 7.8–7.3 (m, 17H, Ar–H); 7.0 (d, 1H, JHH 9.3, Ar–H); 2.4 (s,
3H, CH3)
4
38.1
38.1
38.1
38.7
16.1 (s, 1H, OH); 8.7 (d, 1H, JHH 8.7, Ar–H); 7.8–7.3 (m, 17H, Ar–H); 7.0 (d, 1H, JHH 9.3, Ar–H); 2.7 (q,
2H, JHH 7.8, CH2); 1.3 (t, 3H, JHH 7.8, CH3)
16.2 (s, 1H, OH); 8.7 (d, 1H, JHH 8.9, Ar–H); 7.8–7.3 (m, 17H, Ar–H); 7.0 (d, 1H, JHH 9.3, Ar–H); 3.0
(sp, 1H, JHH 6.7, CH); 1.3 (d, 6H, JHH 6.7, CH3)
16.2 (s, 1H, OH); 8.7 (d, 1H, JHH 8.7, Ar–H); 7.8–7.4 (m, 17H, Ar–H); 7.0 (d, 1H, JHH 9.3, Ar–H); 1.4 (s,
9H, CH3)
8.7 (d, 1H, JHH 6.9, Ar–H); 8.0 (d, 1H, JHH 12.0, Ar–H); 7.8 (d, 1H, JHH 8.4, Ar–H); 7.6–7.3 (m, 16H,
Ar–H); 2.5 (s, 3H, OCCH3); 2.3 (s, 3H, CH3)
5
6
7
1
8
21.1 JW-P 242.6 16.1 (s, 1H, OH); 8.7 (d, 1H, JHH 8.6, Ar–H); 7.8–7.3 (m, 17H, Ar–H); 7.0 (d, 1H, JHH 9.5, Ar–H); 2.4 (s,
3H, CH3)
9
38.7
38.6
38.6
38.6
38.6
38.9
16.1 (s, 2H, OH); 8.3 (d, 2H, JHH 8.7, Ar–H); 7.7 (d, 2H, JHH 8, Ar–H); 7.5–7.3 (m, 34H, Ar–H); 6.7 (d,
2H, JHH 9.7, Ar–H).
16.0 (s, 2H, OH); 8.3 (d, 2H, JHH 7.6, Ar–H); 7.6–7.2 (m, 34H, Ar–H); 6.8 (d, 2H, JHH 9.3, Ar–H); 2.4 (s,
6H, CH3)
16.1 (s, 2H, OH); 8.3 (d, 2H, JHH 8.7, Ar–H); 7.6 (d, 2H, JHH 10, Ar–H); 7.6–7.3 (m, 32H, Ar–H); 6.8 (d,
2H, JHH 9.4, Ar–H); 2.7 (q, 4H, JHH 7.6, CH2); 1.3 (t, 3H, JHH 7.6, CH3)
16.1 (s, 2H, OH); 8.4 (d, 2H, JHH 8.7, Ar–H); 7.7–7.2 (bm, 34H, Ar–H); 6.8 (d, 2H, JHH 9.3, Ar–H); 6.8
(d, 2H, JHH 9.3, Ar–H); 2.7 (sp, 2H, JHH 6.6, CH); 1.3 (d, 12H, JHH 6.6, CH3)
16.1 (s, 2H, OH); 8.4 (d, 2H, JHH 8.9, Ar–H); 7.7–7.2 (bm, 34H, Ar–H); 6.8 (d, 2H, JHH 9.4, Ar–H); 1.4
(s, 18H, CH3)
10
11
12
13
14
8.4 (d, 1H, JHH 8.8, Ar–H); 7.8 (d, 1H, JHH 8.3, Ar–H); 7.6–7.3 (bm, 17H, Ar–H); 2.5 (s, 3H, OCCH3);
2.3 (s, CH3)
J, Hz; s, singlet; d, doublet; t, triplet; sp, septet; m, multiplet; b, broad.
a Spectra recorded in CDCl3 (298 K) and referenced to CHCl3.
b Spectra recorded in CDCl3 (298 K) and referenced to 85% H3PO4.
cis-orientation of the phosphine ligands leads to lo-
calised C2v symmetry. On heating several of the com-
pounds for extended periods only the initial cis isomer
was recovered: there was no evidence for the formation
of the trans isomer. Cotton et al. reported that the
isomerisation process between the cis and trans isomers
is dependent upon the steric and electronic properties of
the phosphines [10], it is apparent for these azo-phos-
phines the cis-orientation is preferred.
unstable (see Tables 1–3 for characterising data).
Treatment of 14 with 2 mole equivalents piperidine
under the conditions used to prepare 9–13 readily
afforded 10 and the amide C5H9NHC(O)Me VII,
whose spectroscopic data were compared with an au-
thentic speciemen. [11] Further, treatment of 7 and VI
with piperidene under the same reaction conditions led
to the isolation of 3, II, and VII, respectively, showing
the de-esterification process by piperidine is quite gen-
eral. If a slight excess of piperidine is added to a CDCl3
solution of II, 7 or 14 and their 1H-NMR spectra
recorded immediately no evidence for the ester moiety
is observed. The CH3 signal at 2.5 ppm attributable to
the ester moiety was replaced by a CH3 signal at 1.98
ppm due to VII; however, the resonance due to the
hydroxyl peak at 16.3 ppm is not observed as this is
deprotonated by the excess piperidine. It is likely then
that de-esterification begins immediately after the initial
substitution of the piperidine ligand, with the displaced
piperidine reacting with both complexed and uncom-
plexed azo-phosphine, implying that it is not an inno-
cent spectator in these substitution reactions.
1
As for 1–8 the H-NMR spectra of 9–13 displayed
the expected resonances for the phosphine ligands; and
the 31P{1H}-NMR spectra all of the compounds exhib-
ited the expected singlet resonance downfield from the
uncomplexed phosphine.
Treatment of [Mo(CO)4(pip)2] with VI did not, how-
ever, yield the expected complex [Mo(CO)4(VI)2] 14
rather 10 was isolated in good yield. This result was
initially a little perplexing, as VI was readily incorpo-
rated into the pentacarbonyl complexes by a simple
ligand substitution reaction. On reflection, though, the
reactivity observed could be easily rationalised using
the following information. Reaction of 10 with a stoi-
chiometric amount of NaH followed by an excess of
MeC(O)Cl yielded [Mo(CO)4(VI)2] 14 in good yield,
which implies that this compound is not intrinsically
Although it is well known that amides can be pre-
pared from esters, it can sometimes be difficult to
achieve unless the ester is activated [12]. It is apparent

282
M.J. Alder et al. / Journal of Organometallic Chemistry 568 (1998) 279–285
Table 5
that hydroxyazonaphthyl systems prefer to exist as the
keto-hydrazone tautomer [1,13,14] and the rapidity of
the de-esterification of the azo-phosphine and amide
formation reported here, is presumably, facilitated by
tautomerisation process activating the ester moiety to
this reaction.
Atomic coordinates (×104) and equivalent isotropic displacement
2
3
˚
parameters (A ×10 ) for 4
Atom
x
y
z
Ueq
Mo(1)
O(1)
O(2)
O(3)
O(4)
O(5)
O(6)
N(1)
N(2)
P(1)
C(1)
C(8)
C(7)
C(6)
C(5)
C(4)
C(3)
4381(1)
2440(1)
6488(3)
4333(4)
3920(4)
1135(4)
3840(4)
636(4)
9164(1)
4699(3)
9655(4)
30(1)
47(1)
70(1)
72(1)
60(1)
66(1)
64(1)
31(1)
35(1)
27(1)
29(1)
31(1)
32(1)
27(1)
27(1)
33(1)
35(1)
33(1)
29(1)
28(1)
32(1)
39(1)
42(1)
39(1)
52(2)
47(2)
55(2)
54(2)
29(1)
44(1)
54(2)
53(2)
50(2)
41(1)
31(1)
38(1)
48(2)
51(2)
47(1)
39(1)
39(1)
45(1)
44(1)
42(1)
41(1)
8097(4)
7243(5)
4505(6)
5971(5)
2652(5)
1530(5)
7981(4)
8576(5)
4549(1)
7470(5)
6897(5)
6249(5)
5500(5)
5486(5)
6180(6)
6839(6)
7509(5)
6846(5)
6155(5)
9052(5)
9852(6)
10386(6)
10153(6)
9324(7)
8787(6)
10766(8)
10313(7)
5475(5)
6773(6)
7514(7)
6954(8)
5672(7)
4935(6)
2980(5)
2765(6)
1588(6)
639(7)
2.1. Molecular structure of 4
11402(4)
10759(4)
7884(4)
8852(4)
4329(3)
3802(3)
7363(1)
5021(4)
5594(4)
6130(4)
6712(4)
6782(4)
6350(4)
5871(4)
5179(4)
5615(4)
6248(4)
3027(4)
2603(5)
1879(5)
1560(5)
1987(6)
2711(5)
801(6)
−386(6)
7614(4)
8432(5)
8656(6)
8065(6)
7262(5)
7028(5)
6158(4)
5041(4)
4154(5)
4363(6)
5449(5)
6344(5)
9460(4)
10582(5)
8948(5)
10161(5)
8302(5)
The molecular structure and molecular numbering
scheme for 4 can be found in Fig. 2. Of particular
interest are the bond lengths around the formal azo
link. Table 7 compares the accepted lengths of single
and double bonds and the observed bond lengths in 4
([15]). What becomes immediately apparent is that the
azo-phosphine exists primarily as the keto-hydrazone
tautomer not the hydroxy-azo tautomer (Fig. 3), since
the C–O and N–C bonds lengths show some multiple
bond character, whereas the N–N bond shows reduced
double bond character. This is further supported by the
location of H(2n) during the structural determination
4110(3)
4777(4)
1420(1)
4599(4)
2732(4)
2020(4)
2386(4)
3507(4)
5427(4)
6157(4)
5789(4)
3848(4)
4248(4)
4268(4)
5024(5)
4577(5)
3407(5)
2674(5)
3100(5)
2940(6)
3139(6)
412(4)
C(2)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
˚
which was found to be 0.96 (8) A from N(2) and is
indicative of an N–H bond [15]. The data summarised
in Table 8 shows that there is also an NH···O hydrogen
bond [15]: an observation that has previously been
Table 4
Crystal data and structure refinement for 4
Empirical formula
Formula weight
Temperature (K)
C35H25MoN2O6P
696.48
203(2)
826(5)
97(6)
−1054(6)
−1477(5)
−750(5)
521(4)
˚
Wavelength (A)
0.71069
(
Crystal system, space group
Unit cell dimensions
Triclinic, P1
˚
a (A)
11.054(2)
12.356(2)
12.761(2)
98.005(15)
108.620(16)
106.567(19)
1531.3(5)
2
˚
606(5)
b (A)
˚
−157(5)
−992(5)
−1080(5)
−324(4)
3667(5)
3357(5)
1248(5)
1566(5)
3336(5)
c (A)
h (°)
i (°)
k (°)
843(6)
2008(6)
6218(6)
4435(6)
2555(7)
5403(6)
3296(6)
3
˚
V (A )
Z
Dcalc. (mg m−3
)
1.510
0.531
708
Absorption coefficient (mm−1
F(000)
)
Crystal size (MM)
Theta range for data collection
0.30×0.25×0.20
1.74–24.97
(°)
Limiting indices
05h513, −145k514,
−155l514
5620/5311 [Rint=0.0280]
24.97 (98.7%)
made in hydroxyazonaphthalene systems [1,13,14]. All
of the other bond lengths are as expected and warrant
no further comment.
Reflections collected/unique
Completeness to theta
Refinement method
Full-matrix least-squares on
F2
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I\2|(I)]
R indices (all data)
5311/0/482
1.036
R1=0.0516, wR2=0.1105
R1=0.0945, wR2=0.1262
3. Conclusion
By simple ligand substitution reactions a series of
azo-phophine Group 6 metal carbonyl complexes have
been prepared. In carrying out these reactions care
must be exercised to prevent the displaced ligand react-
Largest difference peak and hole 0.443 and −0.350
−3
˚
(e A
)

M.J. Alder et al. / Journal of Organometallic Chemistry 568 (1998) 279–285
283
Table 6
Table 6 (Continued)
Bond lengths (A) and angles (°) for 4
C(34)–Mo(1)–P(1)
N(2)–N(1)–C(1)
N(1)–N(2)–C(11)
C(25)–P(1)–C(19)
C(25)–P(1)–C(6)
C(19)–P(1)–C(6)
C(25)–P(1)–Mo(1)
C(19)–P(1)–Mo(1)
C(6)–P(1)–Mo(1)
N(1)–C(1)–C(9)
N(1)–C(1)–C(2)
C(9)–C(1)–C(2)
C(7)–C(8)–C(9)
C(8)–C(7)–C(6)
C(5)–C(6)–C(7)
C(5)–C(6)–P(1)
C(7)–C(6)–P(1)
C(6)–C(5)–C(10)
C(3)–C(4)–C(10)
C(4)–C(3)–C(2)
O(1)–C(2)–C(3)
O(1)–C(2)–C(1)
C(3)–C(2)–C(1)
C(8)–C(9)–C(10)
C(8)–C(9)–C(1)
C(10)–C(9)–C(1)
C(5)–C(10)–C(9)
C(5)–C(10)–C(4)
C(9)–C(10)–C(4)
C(16)–C(11)–C(12)
C(16)–C(11)–N(2)
C(12)–C(11)–N(2)
C(13)–C(12)–C(11)
C(14)–C(13)–C(12)
C(13)–C(14)–C(15)
C(13)–C(14)–C(17)
C(15)–C(14)–C(17)
C(16)–C(15)–C(14)
C(11)–C(16)–C(15)
C(14)–C(17)–C(18)
C(20)–C(19)–C(24)
C(20)–C(19)–P(1)
C(24)–C(19)–P(1)
C(19)–C(20)–C(21)
C(22)–C(21)–C(20)
C(23)–C(22)–C(21)
C(22)–C(23)–C(24)
C(19)–C(24)–C(23)
C(30)–C(25)–C(26)
C(30)–C(25)–P(1)
C(26)–C(25)–P(1)
C(27)–C(26)–C(25)
C(28)–C(27)–C(26)
C(29)–C(28)–C(27)
C(28)–C(29)–C(30)
C(25)–C(30)–C(29)
O(2)–C(31)–Mo(1)
O(3)–C(32)–Mo(1)
O(6)–C(33)–Mo(1)
O(4)–C(34)–Mo(1)
O(5)–C(35)–Mo (1)
92.82(15)
117.0(4)
117.9(4)
102.4(2)
103.3(2)
101.9(2)
118.81(16)
113.40(15)
115.01(15)
115.9(4)
124.2(4)
119.9(4)
121.5(5)
121.0(5)
118.3(4)
120.1(4)
121.6(4)
121.3(4)
122.4(5)
121.5(5)
120.6(5)
121.5(5)
117.9(4)
117.9(4)
122.8(5)
119.3(4)
119.9(4)
121.4(5)
118.7(4)
119.9(5)
123.4(5)
116.8(5)
119.1(5)
122.2(5)
116.9(5)
121.7(5)
121.4(5)
121.8(6)
120.1(5)
114.6(6)
118.1(5)
118.6(4)
123.4(4)
120.8(6)
120.0(6)
120.0(6)
120.2(6)
121.0(6)
118.4(5)
119.0(4)
122.4(4)
119.5(5)
120.8(6)
120.0(6)
119.9(6)
121.4(5)
177.9(5)
177.4(5)
176.5(5)
176.0(5)
174.8(5)
Mo(1)–C(32)
Mo(1)–C(35)
Mo(1)–C(33)
Mo(1)–C(31)
Mo(1)–C(34)
Mo(1)–P(1)
O(1)–C(2)
O(2)–C(31)
O(3)–C(32)
O(4)–C(34)
O(5)–C(35)
O(6)–C(33)
N(1)–N(2)
N(1)–C(1)
N(2)–C(11)
P(1)–C(25)
P(1)–C(19)
P(1)–C(6)
C(1)–C(9)
C(1)–C(2)
C(8)–C(7)
C(8)–C(9)
C(7)–C(6)
C(6)–C(5)
C(5)–C(10)
C(4)–C(3)
1.970(5)
2.031(6)
2.039(6)
2.039(6)
2.055(6)
2.5500(13)
1.275(6)
1.120(6)
1.141(6)
1.122(6)
1.132(7)
1.126(7)
1.300(5)
1.353(6)
1.414(7)
1.824(5)
1.825(5)
1.827(4)
1.440(6)
1.442(7)
1.369(7)
1.393(7)
1.398(7)
1.379(6)
1.401(6)
1.335(7)
1.436(7)
1.426(7)
1.407(7)
1.360(7)
1.386(7)
1.378(8)
1.370(8)
1.393(8)
1.489(8)
1.369(8)
1.515(9)
1.373(8)
1.380(7)
1.381(8)
1.370(9)
1.353(9)
1.378(8)
1.376(7)
1.392(7)
1.387(8)
1.370(9)
1.356(9)
1.383(8)
87.6(2)
C(4)–C(10)
C(3)–C(2)
C(9)–C(10)
C(11)–C(16)
C(11)–C(12)
C(12)–C(13)
C(13)–C(14)
C(14)–C(15)
C(14)–C(17)
C(15)–C(16)
C(17)–C(18)
C(19)–C(20)
C(19)–C(24)
C(20)–C(21)
C(21)–C(22)
C(22)–C(23)
C(23)–C(24)
C(25)–C(30)
C(25)–C(26)
C(26)–C(27)
C(27)–C(28)
C(28)–C(29)
C(29)–C(30)
C(32)–Mo(1)–C(35)
C(32)–Mo(1)–C(33)
C(35)–Mo(1)–C(33)
C(32)–Mo(1)–C(31)
C(35)–Mo (1)–C(31)
C(33)–Mo (1)–C(31)
C(32)–Mo(1)–C(34)
C(35)–Mo(1)–C(34)
C(33)–Mo(1)–C(34)
C(31)–Mo(1)–C(34)
C(32)–Mo(1)–P(1)
C(35)–Mo(1)–P(1)
C(33)–Mo(1)–P(1)
C(31)–Mo(1)–P(1)
90.3(2)
86.8(2)
86.9(2)
93.7(2)
177.1(2)
87.2(2)
174.2(2)
90.7(2)
88.6(2)
173.96(17)
92.59(15)
95.72(16)
87.08(15)

284
M.J. Alder et al. / Journal of Organometallic Chemistry 568 (1998) 279–285
Table 7
afforded analytically pure 1·CH2Cl2. (See Table 1 for
physical and analytical data).
Comparison of formal bond lengths and those observed in 4
˚
˚
˚
C–O (A)
N–N (A)
N–C (A)
4.2. [Mo(CO)5(PhN2-1-C10H5-2-OH-6-PPh2)] (2)
Double bond
Single bond
4
1.2391
1.3691
1.275(6)
1.2491
1.4494
1.300(5)
1.35295a
1.426912
1.353(6)
To [Mo(CO)6] (0.07 g, 0.27 mmol) dissolved in
NCMe (10 cm3) was added Me3NO·2H2O (0.03 g, 0.29
mmol) and the solution was stirred under reduced
pressure for 45 min. To the resulting solution I (0.13g,
0.29 mmol) was added and the solution stirred for 2 h.
After removal of the solvent in vacuo the crude product
was passed down a silica column 2×8 cm with
CH2Cl2:hexane (9:1) as eluent. Removal of the solvent
afforded analytically pure 2.
a Shortened partial double bond in heterocyclic systems, e.g. C5H5N
[16].
ing with the incoming phosphine. These azo-phosphines
exist as the expected keto-hydrazone tautomer.
In analogous reactions treatment of [Mo(CO)5(NC-
Me)] generated in situ with an equimolar quantity of L
(L=4-R–PhN2-1-C10H5-2-OR%-6-PPh2; R%=H, R=
Me, Et, Pri, But; R%=C(O)Me, R=Me) afforded the
complexes [Mo(CO)5L] 3–7. (See Table 1 for physical
and analytical data).
4. Experimental
All solvents were dried by refluxing over an appropri-
ate drying agent and distilled prior to use. The azo-
phosphines were prepared by the published method [1]
as were [M(CO)5(NCMe)] (M=Cr, Mo, W) and
[Mo(CO)4(pip)2] [3,4]; all other chemicals were pur-
chased from commercial sources and used as received.
1H-NMR (200.2 MHz) and 31P {1H}-NMR (81.3 MHz)
were recorded on a Bruker AC200 spectrometer. 1H
were referenced to CHCl3 (l=7.26) and 31P {1H}-
NMR were referenced externally to 85% H3PO4. Ele-
mental analyses were performed by the Microanalytical
service, Department of Chemistry, UMIST. The synthe-
sis of all the carbonyl complexes were carried out under
a dinitrogen atmosphere using standard Schlenk tech-
niques. Work-ups were generally carried out under
dinitrogen unless otherwise stated, although work-up in
the open is possible in some cases, and chromato-
graphic separations were carried out on silica 60 mesh
using CH2Cl2 as eluent.
4.3. [W(CO)5(4-Me–PhN2-1-C10H5-2-OH-6-PPh2)] (8)
To [W(CO)6] (0.11 g, 0.31 mmol) dissolved in NCMe
(10 cm3) was added Me3NO·2H2O (0.34 g, 0.31 mmol)
and the solution was stirred under reduced pressure for
45 min. To the resulting solution II (0.15 g, 0.34 mmol)
was added and the solution stirred for 2 h. After
removal of the solvent in vacuo the crude product was
passed down
a
silica column 2×8 cm with
CH2Cl2:hexane (9:1) as eluent. Removal of the solvent
afforded analytically pure 8. (See Table 1 for physical
and analytical data).
4.4. [Mo(CO)4(PhN2-1-C10H5-2-OH-6-PPh2)] (9)
To cis-[Mo(CO)4(pip)2] (0.044 g, 0.12 mmol) dis-
solved in CHCl2 (25 cm3) was added I (0.1 g, 0.24
mmol) and the solution heated to reflux for 2 h. After
cooling HCl (0.2 cm3) was added and the solution
filtered and the solvent removed under reduced pres-
sure. The crude product was then passed down a short
silica column 2×8 cm with CH2Cl2 as eluent. Removal
of the solvent afforded analytically pure 9·34CH2Cl2.
In analogous reactions treatment of [Mo(CO)4(pip)]
with two molar equivalents of L (L=4-R–PhN2-1-
C10H5-2-OH-6-PPh2; R=Me, Et, Pri, But) afforded the
complexes [Mo(CO)5L] 10–13. (See Table 1 for physi-
cal and analytical data).
4.1. [Cr(CO)5(4-Me–PhN2-1-C10H5-2-OH-6-PPh2)] (1)
To [Cr(CO)6] (0.058 g, 0.26 mmol) dissolved in
NCMe (10 cm3) was added Me3NO.2H2O (0.029 g, 0.26
mmol) and the solution was stirred under reduced
pressure for 45 min. To the resulting solution II (0.13 g,
0.29 mmol) was added and the solution stirred for 2 h.
After removal of the solvent in vacuo the crude product
was passed down a silica column 2×8 cm with
CH2Cl2:hexane (9:1) as eluent. Removal of the solvent
Table 8
Hydrogen bond data for 4
4.5. [Mo(CO)4{4-Me–PhN2-1-C10H5-2-OC(O)-
Me-6-PPh2}] (14)
D–H···A
d (D–H)
(A)
d (H···A)
(A)
d (D···A)
(A)
Ú(DHA)
(°)
˚
˚
˚
To 10 (0.14 g, 0.13 mmol) dissolved in THF (15 cm3)
NaH (0.02 g, 0.26 mmol) under a stream of dry N2 was
added and allowed to stir. After 1 h MeC(O)Cl (0.05 g,
N(2)
0.96(8)
1.69(8)
2.532(6)
145(7)
–H···O(1)

M.J. Alder et al. / Journal of Organometallic Chemistry 568 (1998) 279–285
285
Fig. 2. ORTEP drawing for 4 showing the atomic numbering scheme.
64 mmol) was added and the resulting solution stirred
for a further 2 h. After removal of solvent under
reduced pressure the crude product was extracted into
CH2Cl2 and filtered. Subsequent purification by passing
the crude material through a short silica column af-
forded analytically pure 14. (See Table 1 for physical
and analytical data).
was used to solve the structure by direct methods and
refined using full-matrix least-squares.
Acknowledgements
M.J. Alder and W.I. Cross would like to thank the
EPSRC for the award of postgraduate studentships.
4.6. Crystallography
The X-ray diffraction experiment was carried out at
203 K on a Nonius MACH 4-circle diffractometer
using graphite monochromated Mo–Kh radiation. Lat-
tice constants were determined from the setting angles
of 25 accurately controlled reflections 22.2B2q B
28.3°. The ꢀ/2q scan technique was used with ꢀ scan
width of 0.9°+0.35 tan q to collect 5620 reflections
with 2q 550°. three standard reflections were mea-
sured every 3 h and showed no significant decay. The
intensities were corrected for Lorenz and polarisation
effects but absorbtion was ignored. Crystallographic
data are summarised in Table 4; atom coordinates,
bond lengths and angles are presented in Tables 5 and
6, respectively. The SHELX-97 suite of programs [16]
References
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Fig. 3. Tautomerism displayed by the hydroxyazonaphthylphosphine
complexes 1–6, 8–13.
.