Synthesis, structural characterisation and reactivity of molybdenum half-sandwich complexes containing keto- and amido-phosphines

C D  Andrews; A D  Burrows; J C  Jeffery; J M  Lynam; M F  Mahon

Synthesis, structural characterisation and reactivity of molybdenum half-sandwich complexes containing keto- and amido-phosphines

C D Andrews, A D Burrows, J C Jeffery, J M Lynam, M F Mahon

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

The keto-functionalised N-pyrrolyl phosphine ligand PPh2NC4H3{C(O)CH3-2}. L-1 reacts with [MoCl(CO)(3)(eta(5)-C5R5)] (R = H, Me) to give [MOCl(CO)(2)(L-1-kappa(1)P)(eta(5)-C5R5)] (R = H 1a; Me 1b). The phosphine ligands PPh2CH2C(O)Ph (L-2) and Pph(2)CH(2)C(O)NPh2 (L-3) react with [MoCl(CO)(3)(eta(5)-C5R5)] in an analogous manner to give the compounds [MoCl(CO)(2)(L-kappa(1)P)(eta(5)-C5R5)] (L = L-2, R=H 2a, Me 2b; L=L-3, R = H 3a, Me 3b). Compounds 1-3 react with AgBF4 to give [MO(CO)2(L-kappa(2) P,O)(eta(5) -C5R5)]BF4 (L = L-1, R = H 4a, Me 4b; L = L-2, R = H 5a, Me 5b; L = L-3, R = H 6a, Me 6b) following displacement of chloride. The X-ray crystal structure of 4a revealed a lengthening of both Mo-P and C=O bonds on co-ordination of the keto group. The lability of the co-ordinated keto or amido group has been assessed by addition of a range of phosphines to compounds 4-6. Compound 4a reacts with PMe3, PMe2Ph and PMePh2 to give [Mo(CO)(2)(L-1-kappa(1)P)(L)(eta(5)-C5H5)]BF4 (L = PMe3 7a; PMe2Ph 7b; PMePh2 7c) but does not react with PPh3, 5a reacts with PMe2Ph, PMePh2 and PPh3 to give [MO(CO)(2)(L-2-kappa(1)P)(L)(eta(5)- C5H5)]BF4 (L = PMe2Ph 8b; PMePh2 8c; PPh3 8d), and 6a reacts with PMe3, PMe2Ph, PMePh2 and PPh3 to give [Mo(CO)(2)(L-3- kappa(1)P)(L)(eta(5) -C5H5)]BF4 (L = PMe3 10a; PMe2Ph 10b; PMePh2 10c; PPh3 10d). No reaction was observed for the pentamethylcyclopentadienyl compounds 4b-6b with PMe3, PMe2Ph, PMePh2 or PPh3. These results are consistent with the displacement of the co-ordinated oxygen atom being influenced by the steric properties of the P,O-ligand, with PPh3 displacing the keto group from L 2 but not from the bulkier Lt. In the reaction of [Mo(CO)(2)(L-2-kappa(2)P,O)(eta(5) -C5H5)]BF4 (5a) with PMe3 the phosphine does not displace the keto group, instead it acts as a base, with the only observed molybdenum-containing product being the enolate compound [Mo(CO)(2){PPh2CH=C(O)Ph-kappa(2)P,O}(eta(5) -C5H5)]9, Compound 9 can also be formed from the reaction of 2a with BuLi or NEt3, and a single crystal X-ray analysis has confirmed the enolate structure. (C) 2002 Elsevier Science B.V. All rights reserved.

Original language	English
Pages (from-to)	15-22
Number of pages	8
Journal	JOURNAL OF ORGANOMETALLIC CHEMISTRY
Volume	665
Issue number	1-2
Publication status	Published - 3 Jan 2003

Keywords

keto-phosphines
amido-phosphines
molybdenum
half-sandwich compounds
COORDINATION CHEMISTRY
PALLADIUM COMPLEXES
MOLECULAR-STRUCTURE
CRYSTAL-STRUCTURES
ENOLATE LIGANDS
KETOPHOSPHINE

Cite this

@article{316954b91408459781e5a069a641cd31,

title = "Synthesis, structural characterisation and reactivity of molybdenum half-sandwich complexes containing keto- and amido-phosphines",

abstract = "The keto-functionalised N-pyrrolyl phosphine ligand PPh2NC4H3{C(O)CH3-2}. L-1 reacts with [MoCl(CO)(3)(eta(5)-C5R5)] (R = H, Me) to give [MOCl(CO)(2)(L-1-kappa(1)P)(eta(5)-C5R5)] (R = H 1a; Me 1b). The phosphine ligands PPh2CH2C(O)Ph (L-2) and Pph(2)CH(2)C(O)NPh2 (L-3) react with [MoCl(CO)(3)(eta(5)-C5R5)] in an analogous manner to give the compounds [MoCl(CO)(2)(L-kappa(1)P)(eta(5)-C5R5)] (L = L-2, R=H 2a, Me 2b; L=L-3, R = H 3a, Me 3b). Compounds 1-3 react with AgBF4 to give [MO(CO)2(L-kappa(2) P,O)(eta(5) -C5R5)]BF4 (L = L-1, R = H 4a, Me 4b; L = L-2, R = H 5a, Me 5b; L = L-3, R = H 6a, Me 6b) following displacement of chloride. The X-ray crystal structure of 4a revealed a lengthening of both Mo-P and C=O bonds on co-ordination of the keto group. The lability of the co-ordinated keto or amido group has been assessed by addition of a range of phosphines to compounds 4-6. Compound 4a reacts with PMe3, PMe2Ph and PMePh2 to give [Mo(CO)(2)(L-1-kappa(1)P)(L)(eta(5)-C5H5)]BF4 (L = PMe3 7a; PMe2Ph 7b; PMePh2 7c) but does not react with PPh3, 5a reacts with PMe2Ph, PMePh2 and PPh3 to give [MO(CO)(2)(L-2-kappa(1)P)(L)(eta(5)- C5H5)]BF4 (L = PMe2Ph 8b; PMePh2 8c; PPh3 8d), and 6a reacts with PMe3, PMe2Ph, PMePh2 and PPh3 to give [Mo(CO)(2)(L-3- kappa(1)P)(L)(eta(5) -C5H5)]BF4 (L = PMe3 10a; PMe2Ph 10b; PMePh2 10c; PPh3 10d). No reaction was observed for the pentamethylcyclopentadienyl compounds 4b-6b with PMe3, PMe2Ph, PMePh2 or PPh3. These results are consistent with the displacement of the co-ordinated oxygen atom being influenced by the steric properties of the P,O-ligand, with PPh3 displacing the keto group from L 2 but not from the bulkier Lt. In the reaction of [Mo(CO)(2)(L-2-kappa(2)P,O)(eta(5) -C5H5)]BF4 (5a) with PMe3 the phosphine does not displace the keto group, instead it acts as a base, with the only observed molybdenum-containing product being the enolate compound [Mo(CO)(2){PPh2CH=C(O)Ph-kappa(2)P,O}(eta(5) -C5H5)]9, Compound 9 can also be formed from the reaction of 2a with BuLi or NEt3, and a single crystal X-ray analysis has confirmed the enolate structure. (C) 2002 Elsevier Science B.V. All rights reserved.",

keywords = "keto-phosphines, amido-phosphines, molybdenum, half-sandwich compounds, COORDINATION CHEMISTRY, PALLADIUM COMPLEXES, MOLECULAR-STRUCTURE, CRYSTAL-STRUCTURES, ENOLATE LIGANDS, KETOPHOSPHINE",

author = "Andrews, {C D} and Burrows, {A D} and Jeffery, {J C} and Lynam, {J M} and Mahon, {M F}",

year = "2003",

month = jan,

day = "3",

language = "English",

volume = "665",

pages = "15--22",

journal = "JOURNAL OF ORGANOMETALLIC CHEMISTRY",

issn = "0022-328X",

publisher = "Elsevier",

number = "1-2",

}

TY - JOUR

T1 - Synthesis, structural characterisation and reactivity of molybdenum half-sandwich complexes containing keto- and amido-phosphines

AU - Andrews, C D

AU - Burrows, A D

AU - Jeffery, J C

AU - Lynam, J M

AU - Mahon, M F

PY - 2003/1/3

Y1 - 2003/1/3

N2 - The keto-functionalised N-pyrrolyl phosphine ligand PPh2NC4H3{C(O)CH3-2}. L-1 reacts with [MoCl(CO)(3)(eta(5)-C5R5)] (R = H, Me) to give [MOCl(CO)(2)(L-1-kappa(1)P)(eta(5)-C5R5)] (R = H 1a; Me 1b). The phosphine ligands PPh2CH2C(O)Ph (L-2) and Pph(2)CH(2)C(O)NPh2 (L-3) react with [MoCl(CO)(3)(eta(5)-C5R5)] in an analogous manner to give the compounds [MoCl(CO)(2)(L-kappa(1)P)(eta(5)-C5R5)] (L = L-2, R=H 2a, Me 2b; L=L-3, R = H 3a, Me 3b). Compounds 1-3 react with AgBF4 to give [MO(CO)2(L-kappa(2) P,O)(eta(5) -C5R5)]BF4 (L = L-1, R = H 4a, Me 4b; L = L-2, R = H 5a, Me 5b; L = L-3, R = H 6a, Me 6b) following displacement of chloride. The X-ray crystal structure of 4a revealed a lengthening of both Mo-P and C=O bonds on co-ordination of the keto group. The lability of the co-ordinated keto or amido group has been assessed by addition of a range of phosphines to compounds 4-6. Compound 4a reacts with PMe3, PMe2Ph and PMePh2 to give [Mo(CO)(2)(L-1-kappa(1)P)(L)(eta(5)-C5H5)]BF4 (L = PMe3 7a; PMe2Ph 7b; PMePh2 7c) but does not react with PPh3, 5a reacts with PMe2Ph, PMePh2 and PPh3 to give [MO(CO)(2)(L-2-kappa(1)P)(L)(eta(5)- C5H5)]BF4 (L = PMe2Ph 8b; PMePh2 8c; PPh3 8d), and 6a reacts with PMe3, PMe2Ph, PMePh2 and PPh3 to give [Mo(CO)(2)(L-3- kappa(1)P)(L)(eta(5) -C5H5)]BF4 (L = PMe3 10a; PMe2Ph 10b; PMePh2 10c; PPh3 10d). No reaction was observed for the pentamethylcyclopentadienyl compounds 4b-6b with PMe3, PMe2Ph, PMePh2 or PPh3. These results are consistent with the displacement of the co-ordinated oxygen atom being influenced by the steric properties of the P,O-ligand, with PPh3 displacing the keto group from L 2 but not from the bulkier Lt. In the reaction of [Mo(CO)(2)(L-2-kappa(2)P,O)(eta(5) -C5H5)]BF4 (5a) with PMe3 the phosphine does not displace the keto group, instead it acts as a base, with the only observed molybdenum-containing product being the enolate compound [Mo(CO)(2){PPh2CH=C(O)Ph-kappa(2)P,O}(eta(5) -C5H5)]9, Compound 9 can also be formed from the reaction of 2a with BuLi or NEt3, and a single crystal X-ray analysis has confirmed the enolate structure. (C) 2002 Elsevier Science B.V. All rights reserved.

AB - The keto-functionalised N-pyrrolyl phosphine ligand PPh2NC4H3{C(O)CH3-2}. L-1 reacts with [MoCl(CO)(3)(eta(5)-C5R5)] (R = H, Me) to give [MOCl(CO)(2)(L-1-kappa(1)P)(eta(5)-C5R5)] (R = H 1a; Me 1b). The phosphine ligands PPh2CH2C(O)Ph (L-2) and Pph(2)CH(2)C(O)NPh2 (L-3) react with [MoCl(CO)(3)(eta(5)-C5R5)] in an analogous manner to give the compounds [MoCl(CO)(2)(L-kappa(1)P)(eta(5)-C5R5)] (L = L-2, R=H 2a, Me 2b; L=L-3, R = H 3a, Me 3b). Compounds 1-3 react with AgBF4 to give [MO(CO)2(L-kappa(2) P,O)(eta(5) -C5R5)]BF4 (L = L-1, R = H 4a, Me 4b; L = L-2, R = H 5a, Me 5b; L = L-3, R = H 6a, Me 6b) following displacement of chloride. The X-ray crystal structure of 4a revealed a lengthening of both Mo-P and C=O bonds on co-ordination of the keto group. The lability of the co-ordinated keto or amido group has been assessed by addition of a range of phosphines to compounds 4-6. Compound 4a reacts with PMe3, PMe2Ph and PMePh2 to give [Mo(CO)(2)(L-1-kappa(1)P)(L)(eta(5)-C5H5)]BF4 (L = PMe3 7a; PMe2Ph 7b; PMePh2 7c) but does not react with PPh3, 5a reacts with PMe2Ph, PMePh2 and PPh3 to give [MO(CO)(2)(L-2-kappa(1)P)(L)(eta(5)- C5H5)]BF4 (L = PMe2Ph 8b; PMePh2 8c; PPh3 8d), and 6a reacts with PMe3, PMe2Ph, PMePh2 and PPh3 to give [Mo(CO)(2)(L-3- kappa(1)P)(L)(eta(5) -C5H5)]BF4 (L = PMe3 10a; PMe2Ph 10b; PMePh2 10c; PPh3 10d). No reaction was observed for the pentamethylcyclopentadienyl compounds 4b-6b with PMe3, PMe2Ph, PMePh2 or PPh3. These results are consistent with the displacement of the co-ordinated oxygen atom being influenced by the steric properties of the P,O-ligand, with PPh3 displacing the keto group from L 2 but not from the bulkier Lt. In the reaction of [Mo(CO)(2)(L-2-kappa(2)P,O)(eta(5) -C5H5)]BF4 (5a) with PMe3 the phosphine does not displace the keto group, instead it acts as a base, with the only observed molybdenum-containing product being the enolate compound [Mo(CO)(2){PPh2CH=C(O)Ph-kappa(2)P,O}(eta(5) -C5H5)]9, Compound 9 can also be formed from the reaction of 2a with BuLi or NEt3, and a single crystal X-ray analysis has confirmed the enolate structure. (C) 2002 Elsevier Science B.V. All rights reserved.

KW - keto-phosphines

KW - amido-phosphines

KW - molybdenum

KW - half-sandwich compounds

KW - COORDINATION CHEMISTRY

KW - PALLADIUM COMPLEXES

KW - MOLECULAR-STRUCTURE

KW - CRYSTAL-STRUCTURES

KW - ENOLATE LIGANDS

KW - KETOPHOSPHINE

M3 - Article

SN - 0022-328X

VL - 665

SP - 15

EP - 22

JO - JOURNAL OF ORGANOMETALLIC CHEMISTRY

JF - JOURNAL OF ORGANOMETALLIC CHEMISTRY

IS - 1-2

ER -