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Reaction of isophthaloyl dichloride with two equivalents of benzylamine in the presence of Et3N gives N,N′-dibenzyl-1,3-isophthaldiamide which reacts with two equivalents of Ph2PCl, in the presence of n-BuLi at −78 °C to give 1,3-C6H4-{C(O)N(PPh2)CH2Ph}2 (1). Reaction of 1 with [PtCl2(cod)] in dichloromethane gives the P,P′,C tridentate bis-chelate [Pt(Cl){1,3-C6H4-{C(O)N(PPh2)CH2Ph}2}] (2), whilst reaction of 1 with two equivalents of [(C3H5)PdCl]2 in thf results in [{PdCl(C3H5)}2 {1,3-C6H4-{C(O)N(PPh2)CH2Ph}2}] (3) in which the ligand bridges two palladium centres. The X-ray structures of 2 and 3 are reported. [Copyright &y& Elsevier]

The synthesis, oxidation and coordination chemistry of new bis(aminophosphines) based on diamines is demonstrated. Ph2PN(CH2Ph)CH2CH2(CH2Ph)NPPh2, iPr2PN(CH2Ph)CH2CH2(CH2Ph)NPiPr2, Ph2PNH(C10H6)2NHPPh2, Ph2PNH(C10H6)(C6H4)NHPPh2 were prepared and tested in the hydroformylation of hex-1-to give aldehydes with poor selectivity (up to l:b=2.5:1) to the desired linear products. Modelling calculations were performed for all ligands. R2 groups enlarge the natural bite angle when going from R2=Ph2 to R2=iPr2 which are more bulky. Most of the ligands seem to be rigid (with flexibility ranges of 25°–46°). Four demonstrative X-ray structures are reported. [Copyright &y& Elsevier]

Reaction of piperazine or homopiperazine with R2PCl [R2=Ph2, OC2H4O, OC6H4O] gives six new bidentate phosphines. Simple bis-chelate and bridging complexes with demonstrative Mo(0), Pd(II), Pt(II) and Ru(II) centres are reported. The crystal structures of Ph2P(O)N(C2H4)2P(O)Ph2, cis-[PdCl2{Ph2PN(C2H4)2NPPh2}] (7) and cis-[PtCl2{Ph2PN(C5H10)NPPh2}][PtcodCl2]2 (15) are reported. In Ph2P(O)N(C2H4)2P(O)Ph2 the central N2C4 ring has a chair conformation and the P&z.dbnd6;O groups are trans. In 7 the piperazine backbone results in P&z.sbnd;Pd&z.sbnd;P bite angle of approximately 95° whilst in 15 the homopiperazine backbone enlarges the bite angle to 97°. [Copyright &y& Elsevier]

Reaction of 5,10-dihydrophenazine with two equivalents of Ph2PCl, in the presence of n-BuLi at −78 °C in thf gives Ph2PN(C6H4)(C6H4)NPPh2 (1)1Ph2PN(C6H4)(C6H4)NPPh2 (1). To a −78 °C thf (40 ml) solution of 5,10-dihydrophenazine (1.053 g, 5.78 mmol) was added dropwise a hexane solution of BuLi (4.8 ml, 2.5 mol dm−3, 12.08 mmol). The mixture was stirred at −78 °C for 1 h and another 30 min at room temperature. The reaction solution was cooled to −78 °C again and to it was added dropwise a solution of diphenylchlorophosphine (2.1 ml, 2.613 g, 11.84 mmol) in thf (10 ml) over 40 min. Stirring was continued for another 1 h at −78 °C and overnight at room temperature. The solution was evaporated to dryness in vacuo and dichloromethane (30 ml) was added. Lithium chloride, which precipitated, was removed by filtration under nitrogen and then the volatiles were evaporated in vacuo to leave a yellow solid. Yield: 2.896 g, 91%; Microanalysis: Found (Calcd) C 78.5 (78.5), H 5.1 (5.1), N 4.8 (5.1)%; 31P–{H} NMR (CDCl3): 61.0 (s) ppm; Selected IR data (KBr): ν(PN) 951 cm−1; FAB+ MS: m/z 550 [M], 551 [M + H+], 573 [M + Na+].1 which can be oxidised with selenium to Ph2P(Se)N(C6H4)(C6 H4)NP(Se)Ph2 (2)2Ph2P(Se)N(C6H4)(C6H4)NP(Se)Ph2 (2). To a dry and degassed toluene (10 ml) solution of selenium (0.029 g, 0.36 mmol) was added solid Ph2PN(C6H4)(C6H4)NPPh2 (0.100 g, 0.18 mmol). The solution was heated to reflux for ca. 2–3 h and allowed to cool to room temperature. The solution was evaporated to dryness in vacuo and the solid was dissolved in dichloromethane (2 ml). The dichloromethane solution was filtered through Celite and diethyl ether (20 ml) was added. The white product was collected by suction filtration and washed with diethyl ether (2 × 10 ml). Yield: 0.112 g, 88%; Microanalysis: Found (Calcd) C 60.3 (61.0), H 3.8 (4.0), N 3.8 (4.0)%; 31P–{H}NMR (CDCl3): 58.5 (s) ppm, 1J(77Se–31P) 832 Hz; selected IR data (KBr): ν(PN) 973 cm−1, ν(PSe) 565 cm−1; FAB+ MS: m/z 708 [M], 709 [M + H]+.2 or coordinated with Pt(II) in cis-[PtCl2{Ph2PN(C6H4)(C6H4)NPPh2}] (3)3cis-[PtCl2{Ph2PN(C6H4)(C6H4)NPPh2}] (3). To a dichloromethane (5 ml) solution of [PtCl2(cod)] (0.068 g, 0.18 mmol) was added solid Ph2PN(C6H4)(C6H4)NPPh2 (0.100 g, 0.18 mmol) and the colourless solution stirred for ca. 2–3 h. The solution was concentrated under reduced pressure to ca. 1 ml and diethyl ether (10 ml) added. The white product was collected by suction filtration and washed with diethyl ether (2 × 10 ml). Yield: 0.118 g, 80%; Microanalysis: Found (Calcd) C 53.0 (53.0), H 3.4 (3.5), N 3.3 (3.4)%; 31P–{H} NMR (CDCl3): 43.3 (s) ppm, 1J(195Pt–31P) 3854.6 Hz; selected IR data (KBr): ν(PN) 949 cm−1, ν(PtCl) 311 and 291 cm−1; FAB+MS: m/z 781 [M–Cl−], 839 [M + Na+], 816 [M].3 The structure of 3 reveals a severely distorted (non-planar) phenazine backbone. [Copyright &y& Elsevier]