Organoimido-complexes of tungsten-(VI)-(V), and -(IV) : crystal and molecular structures of [W(NPh)Cl3(PPh3)2] and [W(NPh)Cl2(PMe3)3]

Abstract

Organoimido-complexes of Tungsten-(vl) =(v), and -(Iv) : Crystal andMolecular Structures of [W(NPh)CI,( PPh,),] and [W( NPh)CI,(PMe3)3] t

Synthesis and Structures of Tungsten (1-Pyridinio)imido Complexes and Their Facile N−N Bond Cleavage1

“…The metrical features found for 12 are similar to those reported for related tungsten imido complexes, such as [WCl 2 (NCH 2 -CHdCH 2 )(CO)(PPh 2 Me) 2 ] 20 and [WCl 2 (NPh)(PMe 3 ) 3 ]. 21 It should be pointed out that pyridine 11b was also obtained in high yield by the reduction conducted in the absence of HNEt 3 -Cl, but in this case no characterizable tungsten complex except for a trace amount of 12 was recovered. Therefore, HNEt 3 Cl is not essential for the reductive N-N bond cleavage of 8b but plays a role in protonating the resultant tungsten complex to give the stable imido complex 12.…”

Synthesis and spectroscopic investigation of the pyrazole complexes. The X-ray structure of [ReOBr 3 (OAsPh 3 )(pzH)]

“…1). The major distortion -an increase in the O(1)-Re-Br angles -appears due to the electronic factors interactions with the oxo ligand and it is commonly observed in octahedral complexes containing a multiply bonding ligand [14,15]. The origin of cis-location of p-acid ligands towards the oxo group seems to be dominated by electronic influence of the multiply bonded ligand, which forces the metal non-bonding d electrons to lie in the in the plane perpendicular to the M-O bond axis.…”

“…The origin of cis-location of p-acid ligands towards the oxo group seems to be dominated by electronic influence of the multiply bonded ligand, which forces the metal non-bonding d electrons to lie in the in the plane perpendicular to the M-O bond axis. This general rule appears to hold for isonitrile, carbonyl, olefin, acetylene, thioether and often phosphine ligands [14][15][16][17] [26,27]. The bond valences were computed as m ij ¼ exp½ðR ij À d ij Þ=B [28][29][30], where R ij is the bond-valence parameter (in the formal sense R ij is the single-bond length between i and j atoms) [31].…”

The Molecular and Electronic Structure of [ReOX3(AsPh3)(OAsPh3)] Complexes (X = Cl, Br)

“…Final coordinates for the non-hydrogen atoms are given in Tables II and III. Both complexes possess distorted octahedral geometry with a meridional arrangement of the three halogen ligands and the AsPh 3 molecule cis to the oxo group. The major distortion, an increase in O2-Re-X angles appears to be due to electronic factors and steric interactions with the oxo group as is commonly observed in octahedral complexes containing a multiply bonding ligand [22][23][24]. The cis-location of -acid ligands to the oxo group seems to be the dominant electronic influence of the multiple bonded ligand, which forces the non-bonding metal d electrons to lie in the plane perpendicular to the M-O bond axis.…”