were added to the mixture which was then stirred for 2 h at
35 ЊC. The solution colour changed from brown to red. The
solvent was removed in vacuo and the residue dissolved in
CH2Cl2, layered with n-hexane and stored at Ϫ20 ЊC overnight.
᎐
Filtration gave [Ni(η-C H )(PPh )C᎐CCH᎐NNHC H ] 3 as a
᎐
᎐
5
5
3
6
5
brick-red powder (0.55 g, 90%), decomp. > 150 ЊC (Found: C,
72.1; H, 5.1; N, 5.4%. C32H27NiN2P requires C, 72.6; H, 5.1; N,
5.3%); νmax/cmϪ1 (C᎐C) 2090(4.5), (C᎐N) 1593(10) (CH Cl );
᎐
᎐
᎐
᎐
2
2
᎐
(C᎐C) 2091(4.3), (C᎐N) 1595(10) (KBr); λmax/nm (CH2Cl2) 350
᎐
(ε/dm3 molϪ1 cmϪ1 12 200); λmax/nm (CH3CN) 354 (ε/dm3 molϪ1
cmϪ1 10 100); δH(CDCl3) 6.51–7.76 [20 H, m, Ph and Ph3P),
5.25 [5 H, s, C5H5], 5.09 [1 H, s, NNH] and 4.22 [1 H, s, CH];
δ (CDCl ) 120.1–143.0 (Ph, PPh ), 113.0 [s, CH᎐N], 93.1 [s,
᎐
C
3
3
5
᎐
᎐
NiC᎐C], 92.4 [s, η -C H ] and 91.4 [d, J(CP) 48 Hz, NiC᎐C].
᎐
᎐
5
5
A similar procedure but with NH2NHC6H5 replaced by NH2-
5
᎐
NHC H (NO ) -2,4 gave [Ni(η -C H )(PPh )C᎐CCH᎐NNHC -
᎐
᎐
6
3
2
2
5
5
3
6
H3(NO2)2-2,4] 4 (0.67 g, 95%) decomp. > 150 ЊC (Found:
C, 61.2; H, 4.0; N, 8.7%. C32H25NiN4O4P requires C, 62.1;
H, 4.1; N, 9.0%); νmax/cmϪ1 (C᎐C) 2082 and (NO ) 1617, 1600
᎐
᎐
2
᎐
(CH Cl ); (C᎐C) 2082 and (NO ) 1615, 1601, (KBr); λmax/nm
᎐
2
2
2
(CH2Cl2) 394 (ε/dm3 molϪ1 cmϪ1 19 600 ); λmax/nm (CH3CN) 394
(ε/dm3 molϪ1 cmϪ1 18 500); δ (CDCl ) 9.17 [1 H, s, CH᎐N], 8.26
᎐
H
3
[3 H, m, C6H3], 6.50–7.81 [15 H, m Ph3P], 6.23 [1 H, m, NNH)
and 5.20 [5 H, s, C5H5]; δC 118–144.4 [m, C6H3(NO2)2], 133.8
[d, J(CP) 41 Hz, o-Ph), 133.1 [d, J(CP) 50 Hz, i-Ph], 130.5
[d, J(CP) 2 Hz, p-Ph], 128.2 [d, J(CP) 11 Hz, m-Ph], 117.0
Scheme 1 Synthetic route to the complexes 1–8 (CO ligands have been
omitted from the Co2(CO)6 moiety for the sake of clarity). (i) H2O/oxalic
acid; (ii) PhNHNH2/Hϩ; (iii) C6H3(NO2)2NHNH2/Hϩ; (iv) CH2(CN)2/
Et3N; (v) C9H7NO2/Et3N; (vi) Co2(CO)8.
᎐
᎐
[s, CH᎐N], 110.9 [s, NiC᎐C], 108.3 [d, J(CP) 48 Hz, NiC᎐C] and
᎐
᎐
᎐
93.5 [s, η5-C5H5].
5
and recrystallized from Et2O–hexane to give green crystals of
᎐
The reaction of [Ni(ꢀ -C H )(PPh )C᎐CCHO] with
᎐
5
5
3
5
᎐
[Ni(η -C H )(PPh )C᎐CH(OEt) ] 1 (0.43 g, 80%), mp 76–77 ЊC
᎐
5
5
3
2
malononitrile and 3-phenyl-5-isoxazolone
(Found: C, 70.6; H, 6.0%. C30H31NiO2P requires C, 70.2;
5
᎐
H, 6.1%). νmax/cmϪ1 (C᎐C) 2112 (CH Cl ); (C᎐C) 2109 (KBr);
A solution of [Ni(η -C H )(PPh )C᎐CCHO] 2 (0.1 g, 0.22
᎐
᎐
᎐
5
5
3
᎐
᎐
2
2
mmol) and CH2(CN)2 (0.015 g, 0.22 mmol) in CH2Cl2 (10 cm3)
was stirred for 10 min. Et3N (3 drops) was added. A rapid
colour change from green to deep red took place. The mixture
was stirred for 2 h, and then the solvent removed at reduced
pressure. The residue was crystallised from chloroform–hexane
mixtures at Ϫ20 ЊC overnight and then filtered to give a red
λmax/nm (CH2Cl2) 305 (ε/dm3 molϪ1 cmϪ1 15 200 ); λmax/nm
(CH3CN) 303 (ε/dm3 molϪ1 cmϪ1 14 900); δH(CDCl3) 7.26–7.72
᎐
[15 H, m, Ph], 5.16 [5 H, s, C H ], 4.92 [1 H, s, C᎐CCH], 3.10
᎐
5
5
[4 H, q, J(HH) 6.8 Hz, OCH2] and 0.89 [6 H, t, J(HH) 6.8 Hz,
CH3]; δC(CDCl3) 134.0 [d, J(CP) 11 Hz, o-Ph], 133.9 [d, J(CP)
48 Hz, i-Ph], 130.2 [d, J(CP) 2 Hz, p-Ph], 128.2 [d, J(CP) 10 Hz,
5
᎐
5
powder, [Ni(η -C H )(PPh )C᎐CCH᎐C(CN) ] 5 (0.098 g, 90%),
᎐
᎐
᎐
5
5
3
2
m-Ph], 114.2 [s, NiC᎐C], 92.7 [s, η -C H ], 82.0 (d, J(CP) 40 Hz,
᎐
5
5
decomp. > 150 ЊC (Found: C, 71.4; H, 4.4; N, 5.8%. C29H21N2-
᎐
᎐
NiC᎐C], 71.7 [s, C᎐CCH], 59.3 s, OCH ] and 15.1 [s, CH ];
᎐
᎐
2
3
NiP requires C, 71.4; H, 4.3; N, 5.7%); νmax/cmϪ1 (C᎐C)
᎐
᎐
δP(CDCl3) 41.24.
2050(10), (CN) 2218(1), 2226(1), (C᎐C) 1534(2.1) (CH Cl );
᎐
2
2
᎐
(C᎐C) 2049(10), (CN) 2216(1), 2225(1), (C᎐C) 1532(2.4)
5
᎐
᎐
᎐
Preparation of [Ni(ꢀ -C H )(PPh )C᎐CCHO], 2
᎐
5
5
3
(KBr); λmax/nm (CH2Cl2) 469 (ε/dm3 molϪ1 cmϪ1 13 000);
A solution of oxalic acid (0.03 g, 0.21 mmol) in H2O (10 cm3)
λmax/nm (CH3CN) 463 (ε/dm3 molϪ1 cmϪ1 11 200); δH(CDCl3)
5
᎐
was added to one of [Ni(η -C H )(PPh )C᎐CH(OEt) ] 1 (0.1 g,
7.33–7.62 [15 H, m, Ph3P], 6.43 [1 H, s, CH], 5.25 [5H, s, C5H5];
δ (CDCl ) 152.8 [d, J(CP) 48 Hz, NiC᎐C], 143.7 [s, HC᎐C],
134.1 [d, J(CP) 11 Hz, o-Ph], 133.2 (d, J(CP) 50 Hz, i-Ph], 131.4
᎐
5
5
3
2
0.2 mmol) in tetrahydrofuran (10 cm3). The reaction mixture
was stirred for 1 h at room temperature and then shaken with
CHCl3 (100 cm3) and water (50 cm3). The CHCl3 layer was
washed with water, dried with magnesium sulfate, and chroma-
tographed (alumina/CH2Cl2–Et2O). The green band was evap-
orated to dryness and the residue crystallised from dichloro-
methane–hexane mixtures to give green crystals of [Ni(η5-
᎐
᎐
᎐
C
3
(d, J(CP) 3 Hz, p-Ph], 129.1 [d, J(CP) 11 Hz, m-Ph], 121.5 [s,
5
᎐
᎐
᎐
NiC᎐C], 114.5 [s, C᎐N], 114.9 [s, C᎐N], 94.2 [s, η -C H ] and
᎐
᎐
᎐
5
5
86.3 [d, J(CP) 2.1 Hz, C(CN)2].
Using the same procedure 3-phenyl-5-isoxazolone, C9H7NO2
and [Ni(η -C H )(PPh )C᎐CCHO] 2 gave purple [Ni(η -C H )-
5
5
᎐
᎐
5
5
3
5
5
᎐
᎐
C H )(PPh )C᎐CCHO] 2 (0.07 g, 80%), mp 118–119 ЊC (Found:
(PPh )C᎐CCH᎐C H NO ] 6 (0.11g, 85%), decomp. > 50 ЊC
᎐
5
5
3
᎐
᎐
9
3
5
2
C, 71.6; H, 5.0%. C26H21NiOP requires C, 71.1; H, 4.8%);
(Found: C, 72.1; H, 4.5; N, 2.3%. C32H25NiN4O4P requires C,
νmax/cmϪ1 (C᎐C) 2079(7) and 2034(3), (CO) 1625(10), 1622(10)
72.2; H, 4.5; N, 2.4%); νmax/cmϪ1 (C᎐C) 2050(6), (CO) 1690(10)
᎐
᎐
᎐
᎐
᎐
᎐
(CH Cl ); (C᎐C) 2081(7) and 2034(3), (CO) 1627(10) (KBr);
(CH Cl ); (C᎐C) 2051(6), (CO) 1692(10), (KBr); λmax/nm
᎐
2
2
᎐
2
2
λmax/nm (CH2Cl2) 364 (ε/dm3 molϪ1 cmϪ1 16 100); λmax/nm
(CH3CN) 359 (ε/dm3 molϪ1 cmϪ1 16 000); δH(CDCl3) 8.41 [1 H,
s, CHO], 7.37–7.70 [15 H, m, Ph] and 5.22 [5 H, s, C5H5];
δC(CDCl3) 174.4 [s, CHO], 133.7 [d, J(CP) 11 Hz, o-Ph], 132.9
(d, J(CP) 49 Hz, i-Ph], 130.5 (d, J(CP) 2 Hz, p-Ph), 128.3
(CH2Cl2) 511 (ε/dm3 molϪ1 cmϪ1 27 800 ); λmax/nm (CH3CN) 507
(ε/dm3 molϪ1 cmϪ1 26 600); δH(CDCl3) 6.95–7.59 [21 H, m, Ph3P,
Ph, CH᎐] and 5.22 [5H, s, C H ]; δ (CDCl ) 140.3 [d, J(CP) 48
Hz, NiC᎐C], 133.9 [d, J(CP) 12 Hz, o-Ph], 133.0 (d, J(CP) 50
Hz, i-Ph], 128.7–131.4 [m, Ph, isoxazolone], 130.7 [d, J(CP)
2 Hz, p-Ph], 128.6 [d, J(CP) 11 Hz, m-Ph], 120.7 [s, NiC᎐C] and
᎐
᎐
5
5
C
3
᎐
᎐
᎐
(d, J(CP) 11 Hz, m-Ph], 124.6 [s, NiC᎐C], 122.8 (d, J(CP) 43 Hz,
NiC᎐C] and 93.27 [s, C H ]; δ (CDCl ) 42.64.
᎐
᎐
96.7 [s, η5-C5H5].
᎐
᎐
5
5
P
3
5
5
᎐
᎐
The reaction of [Ni(ꢀ -C H )(PPh )C᎐CCHO] with hydrazines
The reaction of [Ni(ꢀ -C H )(PPh )C᎐CX] {X ؍
CH(OEt) ,
᎐
᎐
5
5
3
5
5
3
2
CHO and CHC(CN)2} with [Co2(CO)8]
5
᎐
[Ni(η -C H )(PPh )C᎐CCHO] 2 (0.5 g, 1.1 mmol) and phenyl-
᎐
5
5
3
hydrazine, H2NNHC6H5 (0.11 g, 1.1 mmol), were dissolved in
dichloromethane (50 cm3). A few drops of glacial acetic acid
[Co2(CO)8] (0.07 g, 0.22 mmol) was added to a solution of
5
᎐
[Ni(η -C H )(PPh )C᎐CX] {0.22 mmol; X = CH(OEt) and
᎐
5
5
3
2
76
J. Chem. Soc., Dalton Trans., 2002, 75–82