The synthesis, and characterisation, of a new functionalised bis(phosphino)amine Ph2PN(o-C6H4OMe)PPh21 from o-H2NC6H4OMe and 2 equiv. of Ph2PCl in diethyl ether at 0°C is reported. Oxidation of 1 with either aqueous H2O2, elemental S8 or grey Se affords the phosphorus(V) compounds Ph2P(E)N(o-C6H4OMe)P(E)Ph2 (E=O 2; S 3 or Se 4). Partial oxidation of 1 with 1 equiv. of S8 in n-hexane affords the mixed P(III)/P(V) species Ph2P(S)N(o-C6H4OMe)PPh25 in addition to small amounts of 3. Reaction of 1 (or 5) with [MX2(cod)] (M=Pd, Pt; X=Cl or CH3; cod=cycloocta-1,5-diene) affords either cis-[MX2{Ph2PN(o-C6H4OMe)PPh2}] (M=Pd, X=Cl 6; M=Pt, X=Cl 7; M=Pt, X=CH38) or the neutral five-membered chelate complexes [MCl2{Ph2P(S)N(o-C6H4OMe)PPh2}] (M=Pd 9, M=Pt 10) in which P,P- or P,S-chelation respectively was observed. Likewise reaction of [Mo(CO)4(nbd)] (nbd=norbornadiene) or [Cu(MeCN)4]PF6 with 1 gave cis-[Mo(CO)4{Ph2PN(o-C6H4OMe)PPh2}] 11 or [Cu{Ph2PN(o-C6H4OMe)PPh2}2]PF612. Chloro-bridge cleavage and arene elimination of [{RuCl2(p-cym)}2] (p-cym=p-cymene) with 1 (1:2 metal:ligand ratio) affords, in good yield, the octahedral bis chelate ruthenium(II) complex trans-[RuCl2{Ph2PN(o-C6H4OMe)PPh2}2] 13. In contrast, reaction of 1 with two equiv. of [AuCl(tht)] (tht=tetrahydrothiophene) gave the dinuclear complex [(ClAu)Ph2PN(o-C6H4OMe)PPh2(AuCl)] 14 in which the bis(phosphino)amine P,P-bridges two {AuCl} metal fragments. All new compounds have been characterised by a combination of multinuclear NMR [1H, 31P{1H} and 195Pt{1H}], IR spectroscopy and elemental analyses. The molecular structures of six representative examples have been determined by single-crystal X-ray crystallography.

This paper was submitted to the journal Polymer and the definitive published version is available at http://dx.doi.org/10.1016/j.polymer.2015.08.039Polyaniline doped with CSA / PEO conductive nanofibres were produced by electrospinning. The electrospinning window was determined by using a three level, full factorial experimental design. The combined effects of the humidity, voltage and flow rate on the fibre morphology and diameter were examined demonstrating that the ambient humidity is the critical factor affecting the electrospinning process and determining the electrospinning window for a conductive polymer. Low humidity favors the formation of defect free fibres while high humidity either hinders fibre formation or causes the formation of defects on the fibres either due to jet discharge or due to water absorption and phase separation. High level of doping with CSA led to the formation of crystalline structures. Data fitting was used to explore the behavior of conductive polymers in electrospinning and very good agreement between experimental and theoretical predictions was obtained for only a limited range of experimental conditions, whereas deviation was observed for all other sets of conditions

Condensation of Ph₂PCH₂OH with H₂NC₅H₃(OH)N in methanol/toluene gave the new “hybrid” ligand Ph₂PCH₂N(H)C₅H₃(OH)N Ia, which upon phosphorylation with either ClP(O)R₂ (R = Ph, OPh) or ClPR₂ afforded Ph₂PCH₂N(H)C₅H₃(X)N [X = OP(O)Ph₂II; OP(O)(OPh)₂III; OPPh₂IV]. Oxidation of Ia with aqueous H₂O₂ in thf gave Ph₂P(O)CH₂N(H)C₅H₃(OH)N V. The dichloroplatinum(II) complexes 1–4 were prepared from [PtCl₂(cod)] (cod = cycloocta-1,5-diene) and Ia, II or III (2 equiv.) or IV (1 equiv.). Reaction of [AuCl(tht)] (tht = tetrahydrothiophene) with 1 equiv. of Ia gave [AuCl(Ia)] 5. Bridge cleavage of [{RuCl(μ-Cl)(η⁶-p-cymene)}₂], [{RuCl(μ-Cl)(η⁶-C₆Me₆)}₂] or [{MCl(μ-Cl)(η⁵-C₅Me₅)}₂] (M = Rh, Ir) with Ia–IV afforded either monometallic [MCl₂(L)(PR₃)] 6–11 (M = Ru, Rh or Ir; L = η⁶-p-cymene, η⁵-C₅Me₅; PR₃ = Ia, II or III) or P,P′-bridged bimetallic [{MCl₂(L)}₂IV] 12–15 (M = Ru, Rh or Ir; L = η⁶-p-cymene, η⁶-C₆Me₆, η⁵-C₅Me₅) complexes. The neutral ruthenium(II) complexes [RuCl₂(η⁶-p-cymene){P-Ph₂PCH₂N(H)C₅H₃(X)}] (X = OH 6a; X = H 6b) undergo isomerisation in CDCl₃ to give [RuCl(η⁶-p-cymene){P,N(pyridyl)-Ph₂PCH₂N(H)C₅H₃(X)N}]Cl (X = OH 6c; X = H 6d). In contrast aged solutions (ca. 40 d) of 7–15 show no evidence (by ³¹P{¹H} NMR) for P,N(pyridyl)-chelation. The X-ray structures of representative compounds have been determined, and confirm, in the case of 6c/6d, a novel six-membered M–P–C–N–C–N metallacycle.

An isomeric series of seven, square-planar, neutral dichloropalladium(II) complexes cis-PdCl₂{P,P-C₆H₃N(CH₂PPh₂)₂(CO₂H)(OH)} 2a–2g have been synthesised in high yields (70–99%) from PdCl₂(cod) (cod = cycloocta-1,5-diene) and the appropriate ligands C₆H₃N(CH₂PPh₂)₂(CO₂H)–(OH) 1a–1g in CH₂Cl₂. The new ditertiary phosphine C₆H₃N(CH₂PPh₂)₂(3-CO₂H)(4-CO₂H) 3, bearing two remote carboxylic acid groups on the N-arene backbone, was prepared by condensation of H₂NC₆H₃(3-CO₂H)(4-CO₂H) with 2 equiv. of Ph₂PCH₂OH in MeOH. The palladium(II) complex cis-{P,P-PdCl₂C₆H₃N(CH₂PPh₂)₂(3-CO₂H)(4-CO₂H)} 4 was synthesised in an analogous fashion to 2a–2g. Solution NMR (³¹P{¹H}, ¹H), FT-IR, ms and microanalytical data are in full agreement with the proposed structures. Single crystal X-ray studies confirm that, in each case, compounds 2a–2e and 4 are square-planar with normal Pd–P [range 2.2255(11)–2.2529(5) Å]/Pd–Cl [range 2.3292(14)–2.3640(16) Å] bond lengths and P–Pd–P [range 91.586(18)–97.25(4)°] bond angles. These studies also demonstrate the importance of predisposition, with respect to the –N(CH₂PPh₂)₂, –CO₂H and –OH (or a second –CO₂H as in 4) functionalities around the benzene core, and the choice of recrystallisation solvent used with regards to the supramolecular structures observed here for the palladium(II) complexes 2a–2e and 4. Hence in 2a·MeOH, intermolecular O–H⋯Cl hydrogen bonding associates two molecules into a dimer pair with the formation of a 20-membered ring. Two different hydrogen bonded motifs are observed in 2b·0.5Et₂O namely an intermolecular O–H⋯O dimer pair and a 1-D polymeric chain through bifurcated O–H⋯Cl hydrogen bonding. Both 2c·MeOH and 2d·CHCl₃ have 1-D chain structures using intermolecular O–H⋯Cl hydrogen bonding between neighbouring molecules (for 2d·CHCl₃ ) or a combination of O–H⋯O (with a MeOH solvent) and O–H⋯Cl hydrogen bonding (for 2c·MeOH). The structures of 2e·CHCl₃ and 2a·CHCl₃ have similar features in common namely a classic H-bonded head-to-tail arrangement of carboxylic acid groups between molecules and additional intermolecular O–H⋯Cl H-bonds giving rise to ladder structures. Each ring is either 38- (for 2e·CHCl₃ ) or 34-membered (for 2a·CHCl₃ ) in size. In 4·2.5MeOH dimers are connected via MeOH solvates to give a 2-D infinite H-bonded network. The X-ray structures of 4·3DMSO, 2e·2DMSO and 2a·DMSO have also been determined. Whilst 4·3DMSO and 2e·2DMSO form discrete structures, 2a·DMSO forms a 1-D chain through O–H⋯Cl hydrogen bonding. The Pd⋯Pd contacts for all these palladium(II) complexes lie clearly within the non bonding range [7.35–20.69 Å].

An isomeric series of six linear, dinuclear, gold(I) complexes (AuCl)₂{P,P-C₆H₄N(CH₂PPh₂)₂(CO₂H)(OH)} 6a–6f have been synthesised in high yields (>90%) from AuCl(tht) (tht = tetrahydrothiophene) and the appropriate building blocks C₆H₄N(CH₂PPh₂)₂(CO₂H)(OH) 3a–3f in CH₂Cl₂. The diphosphine ligands C₆H₄N(CH₂PPh₂)₂1, 4-CO₂HC₆H₄N(CH₂PPh₂)₂2 and their corresponding digold(I) complexes 4 and 5 have also been prepared. Solution NMR (³¹P{¹H}, ¹H), FT-IR and microanalytical data are in full agreement with the proposed structures. Single crystal X-ray studies confirm that in each case, compounds 4, 5, 6a–6e are linear, with typical Au–P [2.227(4)–2.2349(17) Å]/Au–Cl [2.271(2)–2.325(4) Å] bond lengths and P–Au–Cl [169.37(1)–179.05(4)°] bond angles. Furthermore these studies demonstrate the relationship between regioselectivity, with respect to the –N(CH₂PPh₂)₂, –CO₂H and –OH functionalities around the benzene core, and solid state structures of the gold(I) complexes 6a–6e. In 6a, molecules are associated into pairs through classical intermolecular O–H⋯O hydrogen bonding, whilst in 6b and 6c, dimer pairs are formed using intermolecular O–H⋯Cl hydrogen bonds. 1-D chains of alternate 20-/22- or 8-/18-membered hydrogen bonded rings are propagated using O–H⋯Cl and/or O–H⋯O hydrogen bonds in compounds 6d and 6e. The Au⋯Au separation decreases from 6.179(3) Å (for 6a) to 3.0722(9) Å (for 6e) suggesting that aurophilicity increases within this series. The X-ray structure of a representative diphosphine 3a is also presented.

A new functionalised pyridylphosphine Ph2PCH2N(H)C5H3(Cl-5)N 1 has been synthesized from Ph2PCH2OH and 2-H2NC5H3(Cl-5)N. Reaction of 1 with aqueous H2O2 gave Ph2P(O)CH2N(H)C5H3(Cl-5)N 2. The crystal structures of 1 and 2 reveal, in both cases, dimer pair formation through N–H···Npyridyl or N–H···OP intermolecular hydrogen bonding respectively. Chloro bridge cleavage of either [{RuCl(μ-Cl)(η6-p-MeC6H4Pri)}2], [{RhCl(μ-Cl)(η5-C5Me5)}2] or [{Pd(C12H12N)(μ-Cl)}2] with two equivalents of 1 gave the mononuclear complexes [RuCl2(η6-p-MeC6H4Pri)1] 3, [RhCl2(η5-C5Me5)1] 4 or [PdCl(C12H12N)1] 5 (P trans to N) respectively. The chloro complexes [AuCl(1)] 6, [PtCl2(1)2] 7 and [PdCl2(1)2] 8 were prepared by substitution of tht (tetrahydrothiophene) (or cod) from [AuCl(tht)] or [MCl2(cod)] (M = Pt or Pd). In 3–8 only P-ligation of 1 was observed. Chloride abstraction from either 3–5 or 7, 8 using Ag[BF4] gave the cationic complexes [RuCl(η6-p-MeC6H4Pri){Ph2PCH2N(H)C5H3(Cl-5)N-P,N}][BF4] 9, [RhCl(η5-C5Me5){Ph2PCH2N(H)C5H3(Cl-5)N-P,N}][BF4] 10, [Pd(C12H12N){Ph2PCH2N(H)C5H3(Cl-5)N-P,N}][BF4] 11 and cis-[M{Ph2PCH2N(H)C5H3(Cl-5)N-P,N}2][BF4]2 (M = Pt 12 or Pd 13) in which 1 chelates through both P and Npyridyl donor atoms. All complexes were characterised by a combination of multinuclear NMR, IR spectroscopy and elemental analyses. Furthermore the crystal structures of 5–7 and 12 have been determined and reveal several types of N–H···X (X = N, F or Cl; inter- or intra-molecular) hydrogen bonding contacts. The structure of 12 represents an extremely rare, crystallographically characterised, M–P–C–N–C–N six-membered metallacyle.