Low-Dimensional Architectures in Isomeric cis-PtCl2{Ph2PCH2N(Ar)CH2PPh2} Complexes Using Regioselective-N(Aryl)-Group Manipulation

Abstract

The solid-state behaviour of two series of isomeric, phenol-substituted, aminomethylphosphines, as the free ligands and bound to PtII, have been extensively studied using single crystal X-ray crystallography. In the first library, isomeric diphosphines of the type Ph2PCH2N(Ar)CH2PPh2 [1a–e; Ar = C6H3(Me)(OH)] and, in the second library, amide-functionalised, isomeric ligands Ph2PCH2N{CH2C(O)NH(Ar)}CH2PPh2 [2a–e; Ar = C6H3(Me)(OH)], were synthesised by reaction of Ph2PCH2OH and the appropriate amine in CH3OH, and isolated as colourless solids or oils in good yield. The non-methyl, substituted diphosphines Ph2PCH2N{CH2C(O)NH(Ar)}CH2PPh2 [2f, Ar = 3-C6H4(OH); 2g, Ar = 4-C6H4(OH)] and Ph2PCH2N(Ar)CH2PPh2 [3, Ar = 3-C6H4(OH)] were also prepared for comparative purposes. Reactions of 1a–e, 2a–g, or 3 with PtCl2(η4-cod) afforded the corresponding square-planar complexes 4a–e, 5a–g, and 6 in good to high isolated yields. All new compounds were characterised using a range of spectroscopic (1H, 31P{1H}, FT–IR) and analytical techniques. Single crystal X-ray structures have been determined for 1a, 1b∙CH3OH, 2f∙CH3OH, 2g, 3, 4b∙(CH3)2SO, 4c∙CHCl3, 4d∙½Et2O, 4e∙½CHCl3∙½CH3OH, 5a∙½Et2O, 5b, 5c∙¼H2O, 5d∙Et2O, and 6∙(CH3)2SO. The free phenolic group in 1b∙CH3OH, 2f∙CH3OH,2g, 4b∙(CH3)2SO, 5a∙½Et2O, 5c∙¼H2O, and 6∙(CH3)2SO exhibits various intra- or intermolecular O–H∙∙∙X (X = O, N, P, Cl) hydrogen contacts leading to different packing arrangements.

The Backbone of Success of P,N-Hybrid Ligands: Some Recent Developments

“…Whilst 6q was not isolated, it is clearly an intermediate which subsequently reacts with CH 2 O to form N,N'-bis(phosphinomethyl)-dihydroperimidines. Our group have been interested, for a number of years, in highly decorated ditertiary phosphines with -CO2H and/or -OH functionalities in the N-arene backbone and have found positioning to be important in determining packing arrangements as seen for various Au(I), Pd(II), Pt(II), and Ru(II) metal centres studied [118][119][120][121][122]. The diphosphine 6r forms an unusual hexameric structure in which the ligand acts as a P2O-tridentate ligand [121].…”

“…We have shown, by careful manipulation of the R group on the nitrogen atom, the ability to impact a range of packing motifs through H-bonding patterns at various late transition metal centres. In addition, the position of, for example, -CO2H groups could Our group have been interested, for a number of years, in highly decorated ditertiary phosphines with -CO 2 H and/or -OH functionalities in the N-arene backbone and have found positioning to be important in determining packing arrangements as seen for various Au(I), Pd(II), Pt(II), and Ru(II) metal centres studied [118][119][120][121][122]. The diphosphine 6r forms an unusual hexameric structure in which the ligand acts as a P 2 O-tridentate ligand [121].…”

Phospha-Mannich reactions of RPH2, R2PH, and R3P

“…Entry R R' Yield, % δ P , ppm 53 [148] -27.2 (CDCl 3 ) 71 [248] -26.7 (CDCl 3 ) 90 [249] -27.5 (CDCl 3 ) 93 [250] -8.1 (CDCl 3 ) 86 [242] -25.7 (CDCl 3 ) 53 [251] -27.6 (DMSO-d 6 ) 58 [204,205] -27.3 (CDCl 3 ) 78 [248] -27.5 (CDCl 3 ) 66 [252,253] -26.4 (CDCl 3 ) 73 [242] -26.8 (CDCl 3 ) 79 [254] -27.1 (DMSO-d 6 ) 65 [246,247] -28.3 (CDCl 3 ) 87 [255] -18.3 (CDCl 3 ) 80 [255] -22.3 (CDCl 3 )…”

“…Entry R R' Yield, % δ P , ppm 76 [255] -20.2 (CDCl 3 ) 81 [256] -26.6 (CDCl 3 ) 38 [251] -26.7 (DMSO-d 6 ) ~ 80 [256] -26.7 (CDCl 3 /MeOH) ~ 80 [256] -25.4 (CDCl 3 ) 79 [251] -27.5 (DMSO-d 6 ) 97 [251] -27.5 (DMSO-d 6 ) ~ 80 [256] -28.1 (CDCl 3 ) 56, [251] 74 [248] -27.3 (DMSO-d 6 ), -27.5 (CDCl 3 ) 96 [251] -26.4 (DMSO-d 6 ) 51 [257] -24.8 (DMSO-d 6 ) 99 [177,258] -26.8 (C 7 H 8 ) 91 [210] -27.0 (CDCl 3 )…”

“…Yield, % d P , ppm 64 [143] -26.4 (CDCl 3 ) ~ 99 [143] -26.3 (CDCl 3 ) ~ 99 [143] -28.6 (CDCl 3 ) 57 [143,306] -26.2 (CDCl 3 ) 75 [143] -26.3 (CDCl 3 ) 77 [143] -26.3 (CDCl 3 ) 81 [251] -26.0 (DMSO-d 6 ) 88 [251] -26.5 (CDCl 3 ) 89 [251] -26.0 (DMSO-d 6 ) 65 [251] -27.1 (DMSO-d 6 ) 80 [251] -27.1 (DMSO-d 6 ) 70 [251] -27.5 (DMSO-d 6 ) 85 [251] -26.8 (DMSO-d 6 )…”