Martin B. Smith

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Organization: Loughborough University , England

Department: Department of Chemistry

Title: Lecture(PhD)

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Inorganic Chemistry

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Synthesis, metal coordination and structural studies of trisubstituted P{CH2-1-N(H)naphthyl}3 ligands

Co-reporter:Cameron L. Carpenter-Warren, Matthew Cunnington, Mark R.J. Elsegood, Andrew Kenny, Alex R. Hill, Christopher R. Miles, Martin B. Smith

Inorganica Chimica Acta 2017 Volume 462(Volume 462) pp:

Publication Date(Web):1 June 2017

DOI:10.1016/j.ica.2017.03.024

•Two-step synthesis of three new trisubstituted tertiary phosphines bearing 1-aminonaphthyl groups.•A study of their ligating potential towards RuII, IrIII, PdII, PtII and AuI metal centres.•Structures verified in solution using NMR (1H, 31P) spectroscopy.•Single crystal X-ray crystallography confirmed solid state structures in seven cases.•Different inter/intramolecular H-bonding motifs observed.The two-step synthesis of new naphthyl based P{CH2-1-NHC10H6(4-R)}3 ligands (R = H, L1; R = Cl, L2; R = Br, L3) by initial condensation of [P(CH2OH)4]Cl with 4 equiv of 1-NH2C10H6(4-R) in EtOH, followed by reduction with tBuOK in MeOH, is described. Oxidation of L1 with elemental S or grey Se gave SP{CH2-1-NHC10H6(4-H)}3 SL1 or SeP{CH2-1-NHC10H6(4-H)}3 SeL1 respectively. The two-coordinate Au(I) complex [AuCl(L1)] 4 was prepared from [AuCl(tht)] (tht = tetrahydrothiophene) and one equiv. of L1 in 83% yield. Chloro-bridge cleavage of [RuCl(μ-Cl)(η6-C10H14)]2 or [IrCl(μ-Cl)(η5-Cp∗)]2 with L1, in CH2Cl2, gave the mononuclear complexes [RuCl2(η6-C10H14)L1] 5 and [IrCl2(η5-Cp∗)L1] 6 respectively. Similarly chloro-bridge cleavage of the cyclometallated compounds [Pd(μ-Cl)(κ2-C6H4CH2NMe2)]2 or [Pd(μ-Cl)(κ2-C10H6NMe2)]2 with L1–L3 gave the κ2-PN-chelate complexes [PdCl(κ2-C6H4CH2NMe2)L1–L3] (8–10) or [PdCl(κ2-C10H6NMe2)L1] 11 respectively. Reaction of two equiv. of L1–L3 with [PtCl2(cod)] (M = Pt, cod = cycloocta-1,5-diene), in CH2Cl2, afforded the complexes [MCl2(L1–L3)2] (11–13) as the cis isomers. In contrast, reaction of two equiv. of L1 with [PdCl(CH3)(cod)] gave [PdCl(CH3)(L1)2] 14 exclusively as the trans isomer. All compounds have been characterised by multinuclear NMR, FT-IR, mass spectrometry and microanalysis. Single crystal X-ray studies have been performed on compounds L1, 4, 6·CDCl3·OEt2, 8–10 and 11·CDCl3·OEt2. Intermolecular and/or intramolecular H-bonding is observed in various instances involving the secondary amine groups.The synthesis of three new trisubstituted tertiary phosphines bearing 1-aminonaphthyl groups is reported along with a survey of their coordination capabilities at various RuII, IrIII, PdII, PtII and AuI metal centres. Various inter- and intramolecular H-bonding and X⋯X contacts have been identified using single crystal X-ray crystallography.Download high-res image (60KB)Download full-size image

New (aminomethyl)phosphines via selective hydrophosphination and/or phosphorus based Mannich condensation reactions

Co-reporter:Bo Cao, Mark R.J. Elsegood, Nuria Lastra-Calvo, Martin B. Smith

Journal of Organometallic Chemistry 2017 Volume 853(Volume 853) pp:

Publication Date(Web):15 December 2017

DOI:10.1016/j.jorganchem.2017.10.029

•One-step synthesis of tertiary and ditertiary phosphines bearing an olefinic or primary amine group.•A study of their ligating potential towards RuII, PdII, PtII and AuI metal centres.•P-monodentate or P,P-bridging behaviour observed for the new phosphine ligands.•Structures verified in solution using NMR (1H, 31P) spectroscopy.•Single crystal X-ray crystallography confirmed solid state structures in eight cases.Controlled stepwise reaction of a geminal substituted alkene or primary amine group afforded a small library of new functionalised tertiary and ditertiary phosphines. Accordingly, Mannich based condensation of the commercially available disubstituted arene C6H4(NH2){2-C(Me)=CH2} with HOCH2PR2 (R2 = Cg: 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantyl; Ph2) afforded the (aminomethyl)phosphines C6H4(NHCH2PCg){2-C(Me)=CH2} L1 and C6H4(NHCH2PPh2){2-C(Me)=CH2} L2 in approx. 60% yield. In addition to the formation of L2, the diphosphine L3 was also identified and independently synthesised upon reaction of C6H4(NH2){2-C(Me)=CH2} with two equiv. of HOCH2PPh2 in CH3OH under reflux. Alternatively, reaction of C6H4(NH2){2-C(Me)=CH2} with H-PR2 (R2 = Cg or Ph2) in the presence of AIBN [2,2′-azobis(2-methylpropionitrile)] as free radical initiator, afforded the primary amine functionalised phosphines C6H4(NH2){2-CH(Me)CH2PCg} L4 and C6H4(NH2){2-CH(Me)CH2PPh2} L5 in 85% and 66% isolated yields respectively. In both cases only the anti-Markovnikov addition products were observed. Subsequent reaction of L5 with HOCH2PR2 (R2 = Ph2) afforded the unsymmetrical ditertiary phosphine C6H4(NHCH2PPh2){2-CH(Me)CH2PPh2} L6. Some preliminary coordination studies towards [RuCl(μ-Cl)(η6-C10H14)]2, [AuCl(tht)] (tht = tetrahydrothiophene) and [MCl2(η4-cod)] (M = Pd, Pt; cod = cycloocta-1,5-diene) demonstrate these new ligands behave as classic P-donors leaving the pendant amino or alkenyl groups non-coordinating. All compounds have been characterised by multinuclear NMR, FT−IR, mass spectrometry and microanalysis. Single crystal X-ray studies have been performed on L3, L5, L6, 1, 3b·0.5CH2Cl2, 4a·1.5CH2Cl2, 5 and 6·0.5CDCl3·0.5C4H10O.

Diverse Coordination Behaviour of Phosphorus(V)-Functionalised 6-Chloroaminobenzothiazole Anions at Various Metal Centres

Co-reporter:Simon J. Coles;Sophie H. Dale;Mark R. J. Elsegood;Kirsty G. Gaw;Thomas Gelbrich;Michael B. Hursthouse;Mark E. Light;Thomas A. Noble

European Journal of Inorganic Chemistry 2012 Volume 2012( Issue 5) pp:859-865

Publication Date(Web):

DOI:10.1002/ejic.201100960

Abstract

Aminobenzothiazole-functionalised phosphane 1 and its corresponding phosphorus(V) analogues 2–4 were synthesised in high yields. New 1D polymeric salts K[ClC₆H₃NC(S)NP(E)Ph₂]_∞ (E = O 5; E = S 6) were shown, by using single-crystal X-ray diffraction, to exhibit unique potassium metal ion coordination through either κ³-N₂O tridentate (E = O) or κ²-N₂ bridging (E = S) modes. In contrast, κ²-NE chelation (E = S, Se) was observed upon complexation to a range of metal fragments including {Ir(η⁵-Cp*)Cl} (E = S 8; E = Se 9), {Rh(η⁵-Cp*)Cl} (E = S 10; E = Se 11), {Ru(η⁶-p-MeC₆H₄iPr)Cl} (E = S 12), {Ru(η⁶-C₆Me₆)Cl} (E = S 13) and {Pt(PMe₂Ph)Cl} (E = S 14). All new compounds were characterised by a combination of multinuclear NMR, FTIR and microanalysis. Seven compounds were structurally characterised by using single-crystal X-ray crystallography.

New κ3-PNN′- and κ4-PNN′O-polydentate ligands: Synthesis, coordination and structural studies

Co-reporter:Mark R.J. Elsegood, Noelia M. Sanchez-Ballester, Martin B. Smith

Inorganica Chimica Acta 2011 Volume 379(Issue 1) pp:115-121

Publication Date(Web):15 December 2011

DOI:10.1016/j.ica.2011.09.045

The three-step synthesis of new mixed P/N/N′/O-donor ligands C6H3(OH){2-NHC(O)CH2NCHC6H4PPh2}(4-CH3) 3a·HH and C6H4(OH){3-NHC(O)CH2NCHC6H4PPh2} 3b·HH, by Schiff base condensation of the 1° amines C6H3(OH){2-NHC(O)CH2NH2}(4-CH3) 2a or C6H4(OH){3-NHC(O)CH2NH2} 2b with C6H4(CHO)(2-PPh2) in refluxing EtOH, is described. Reaction of 1 equiv. of 3a·HH or 3b·HH with MCl2(cod) (M = Pt, Pd; cod = cycloocta-1,5-diene) affords the κ2-PN-chelate complexes MCl2(3a·HH) (M = Pd 4a; M = Pt 4b) and MCl2(3b·HH) (M = Pt 4c). The dichlorometal(II) complexes 4d and 4e, bearing instead a pendant 4-phenolic group, were similarly prepared (in >90% yield). Chloro-bridge cleavage of [Pd(μ-Cl)(η3-C3H5)]2 with 3a·HH or 3b·HH gave the monocationic κ2-PN-chelate complexes [Pd(η3-C3H5)(3a·HH)]Cl 5a or [Pd(η3-C3H5)(3b·HH)]Cl 5b, respectively. Elimination of cod, and single CH3 protonation, from Pt(CH3)2(cod) upon reaction with 1 equiv. of 3a·HH or 3b·HH in C7H8 at room temperature afforded the neutral complexes C6H3(OH){2-NC(O)CH2NCHC6H4PPh2Pt(CH3)}(4-CH3) 6a and C6H4(OH){3-NC(O)CH2NCHC6H4PPh2Pt(CH3)} 6b, respectively bearing a monoanionic (3a·H− or 3b·H−) κ3-PNN′-tridentate ligand. Amide and phenol deprotonation were readily achieved, using KOtBu as base, to give high yields of the κ4-PNN′O-tetradentate complexes C6H3(O){2-NC(O)CH2NCHC6H4PPh2Pd}(4-CH3) 7a and C6H3(O){2-NC(O)CH2NCHC6H4PPh2Pt}(4-CH3) 7b bearing the dianionic ligand 3a2−. All new compounds have been characterised by multinuclear NMR, FTIR, mass spectroscopy and microanalysis. Single crystal X-ray studies have been performed on compounds 1b·1.5CH2Cl2, 3b·HH·0.5Et2O, 6b·CHCl3 and 7b·0.5Et2O.Graphical abstractThe synthesis of two new potentially tetradentate ligands bearing a PNN′O donor set combination is reported along with a survey of their PN-, PNN′- and PNN′O-bonding capabilities at square-planar palladium(II) and platinum(II) metal centres.Highlights► Three-step synthesis of nonsymmetric multidentate phosphorus based ligands containing P, N and O donor centres. ► A study of their ligating potential towards PdII and PtII square-planar metal centres. ► Structures verified in solution using NMR (1H and 31P) spectroscopy. ► Single crystal X-ray crystallography confirmed solid state structures in four cases. ► Stepwise coordination of P, N and O donor atoms can be controlled.

Metal(II) template assisted syntheses of two P―C―O―P chelating ligands incorporating a bulky 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantyl cage

Co-reporter:Gavin M. Brown, Mark R.J. Elsegood, Martin B. Smith, Kevin Blann

Inorganic Chemistry Communications 2011 Volume 14(Issue 6) pp:940-943

Publication Date(Web):June 2011

DOI:10.1016/j.inoche.2011.03.037

Unusual Metal-Coordinated Zwitterionic P−C−N−C−N−C Phosphido Adducts

Co-reporter:Allen T. Ekubo ; Mark R. J. Elsegood ; Andrew J. Lake

Inorganic Chemistry 2010 Volume 49(Issue 8) pp:3703-3705

Publication Date(Web):March 18, 2010

DOI:10.1021/ic1002308

Rare examples of homodinuclear zwitterionic PdII and PtII complexes with bridging, two-coordinate P{cyclo-CH2N(R)CHN(R)CH2} ligands (R = 4-FC6H4CH2, C6H5CH2) have been characterized by single-crystal X-ray diffraction using synchrotron radiation. Short N−C distances and enlarged N−C−N bond angles support electron delocalization in the central N−C−N backbone.

Versatile routes to selenoether functionalised tertiary phosphines

Co-reporter:Tom J. Cunningham, Mark R. J. Elsegood, Paul F. Kelly, Martin B. Smith and Paul M. Staniland

Dalton Transactions 2010 vol. 39(Issue 22) pp:5216-5218

Publication Date(Web):19 Apr 2010

DOI:10.1039/C0DT00004C

New selenoether functionalised tertiary phosphines, based on aryl (2a, 2b) or alkyl (4) backbones, have been synthesised and characterised. P,Se-chelation has been achieved upon complexation to square-planar PtII (3a) or PdII (3b) metal centres. For 3a and 3b, weak non-covalent M⋯Se contacts were established using single crystal X-ray crystallography.

Flexible κ4-PNN′O-tetradentate ligands: synthesis, complexation and structural studies

Co-reporter:Sean E. Durran, Mark R. J. Elsegood, Shelly R. Hammond and Martin B. Smith

Dalton Transactions 2010 vol. 39(Issue 30) pp:7136-7146

Publication Date(Web):24 Jun 2010

DOI:10.1039/C0DT00200C

The three-step synthesis of new, air-stable, PNN′O-tetradentate ligands 3a·HH–3c·HH by Schiff base condensation of the 1° amines 2a–2c with 2-Ph2PC6H4(CHO) in refluxing EtOH is described. The racemic ligand 3d·HH, isolated in 79% yield, was successfully prepared from 2-C6H4(OH){C(O)NHCH2CH(Me)NH2} 2d and 2-Ph2PC6H4(CHO) in absolute EtOH. Upon careful choice of metal precursor, ligands 3a·HH–3d·HH display various coordination modes. Reaction of 3a·HH with AuCl(tht) (1:1 molar ratio) affords AuCl(3a·HH), 4a, in which κ1-P-complexation of the functionalised ligand is observed. In contrast, reaction of 3a·HH (or 3d·HH) with MCl2(cod) (M = Pt, Pd) affords MCl2(3a·HH) (M = Pt, 5a; M = Pd, 5b) or MCl2(3d·HH) (M = Pt, 5c; M = Pd, 5d) in which ligand chelation is achieved using both P and imine N donor atoms. Moreover κ2-P,N-chelation was also observed when 3a·HH–3c·HH were separately allowed to react with [PdCl(η3-C3H5)]2 in CH2Cl2 affording new cationic η3-allyl complexes [Pd(η3-C3H5)(3a·HH–3c·HH)]Cl, 6a–6c. Two neutral (methyl)chloropalladium(II) complexes, 7a/7c, were isolated in high yields from 3a·HH or 3c·HH and Pd(CH3)Cl(cod). Elimination of cod and single methyl protonation from Pt(CH3)2(cod) with 1 equiv. of 3a·HH, 3b·HH or 3d·HH in toluene, at room temperature, afforded square-planar complexes Pt(CH3)(κ3-3a·H/3b·H/3d·H), 8a/8b/8d, containing monoanionic κ3-PNN′-tridentate ligands. The κ3-PNN′-tridentate mode was likewise observed for Pd(CH3)(3a·H/3c·H), 10a/10c, upon treatment of a methanolic solution of Pd(CH3)Cl(3a·HH/3c·HH) with tBuOK. Similarly the monohapto (allyl)PdII compounds Pd(CH2CHCH2)(3a·HH–3c·HH), 9a–9c, were obtained cleanly from 6a–6c and tBuOK via an η3→η1 allyl isomerisation. Both amide and phenolic protons in 5a–5d were smoothly deprotonated, with base, to give the κ4-PNN′O-tetradentate complexes 11a/11b and 11d/11e containing the dianionic ligands 3a2−/3d2− respectively. The NiII complexes 11c and 11f were synthesised directly from NiCl2·6H2O, 3a·HH (or 3d·HH) and tBuOK in CH3OH. All new compounds were characterised by multinuclear NMR, FT–IR, mass spectrometry and microanalysis. Single crystal X-ray studies have been undertaken on the compounds 3a·HH, 3c·HH, 4a, 7c, 8a, 8b, 8d and 11a–11d.

A new tris(ferrocenylamine) ditertiary phosphine: Synthesis and co-ordination studies

Co-reporter:Mark R.J. Elsegood, Andrew J. Lake, Roger J. Mortimer, Martin B. Smith, George W. Weaver

Journal of Organometallic Chemistry 2010 695(14) pp: 1838-1842

Publication Date(Web):

DOI:10.1016/j.jorganchem.2010.04.012

Intramolecular Hydrogen-Bonded Tertiary Phosphines as 1,3,5-Triaza-7-phosphaadamantane (PTA) Analogues

Co-reporter:Allen T. Ekubo, Mark R. J. Elsegood, Andrew J. Lake and Martin B. Smith

Inorganic Chemistry 2009 Volume 48(Issue 6) pp:2633-2638

Publication Date(Web):February 11, 2009

DOI:10.1021/ic801709z

New cationic trialkylphosphines [P(CH2NH2R){CH2N(R)CH2N(R)CH2}]+ (R = C6H5CH2, a; 4-FC6H4CH2, b), as their Cl− (1a, 1b), SbF6− (2a, 2b), and PF6− (3a, 3b) salts, are described. The phosphine framework is conformationally locked, in the solid state, through pairs of intramolecular N−H···N hydrogen bonds which are maintained in the RuII and RhIII complexes 4 and 5. Phosphines 1a−3b can be considered as charged variants of the well-known PTA ligand.

A novel fluorene-containing κ4-P2N2-tetradentate platinum(II) complex

Co-reporter:Mark R. J. Elsegood, Andrew J. Lake and Martin B. Smith

Dalton Transactions 2009 (Issue 1) pp:30-32

Publication Date(Web):17 Nov 2008

DOI:10.1039/B816351K

Base induced P,N-chelation, C–C coupling and methylene C–H deprotonation affords an unusual fluorene containing square-planar PtII complex Pt(κ4-P2N2-Ph2PCHNNCC12H8)2 which has been isolated and structurally characterised.

Late Transition-Metal Complexes of 2-Ph2PC6H4NHC(O)CH2NHCO2Bz: Observation of Three Distinct Ligation Modes (1-P,2-P/N and 3-P/N/N)

Co-reporter:Mark R. J. Elsegood;Andrew J. Lake

European Journal of Inorganic Chemistry 2009 Volume 2009( Issue 8) pp:1068-1078

Publication Date(Web):

DOI:10.1002/ejic.200801104

Abstract

The one-step synthesis of the amide-functionalised tertiary phosphane 2-Ph₂PC₆H₄NHC(O)CH₂NHCO₂Bz (Bz = CH₂Ph), 2·HH, by condensation of the known aminophosphane, 2-Ph₂PC₆H₄(NH₂) (1), with N-(benzyloxycarbonyl)glycine and dicyclohexylcarbodiimide (DCC) in THF at room temperature is reported. The new ligand 2·HH displays various coordination modes when complexed to a range of late transition-metal precursors. Hence κ¹-P-coordination for 2·HH is observed in the complexes ClAu(2·HH) (3), MCl₂(η⁵-Cp*)(2·HH) (M = Rh 4; Ir 5), RuCl₂(η⁶-p-cymene)(2·HH) (6), Pd(κ²-CN-C₁₂H₁₂N)Cl(2·HH) (7) and MCl₂(2·HH)₂ (M = Pd 8; Pt 9). Treatment of 8 or 9 with tBuOK in CH₃OH gave the bis-κ²-P/N-chelate complexes cis-M{2-Ph₂PC₆H₄NC(O)CH₂NHCO₂Bz}₂ (M = Pt 10; Pd 11) in which both monoanionic ligands 2·H^– are disposed in a cis geometry. The relatednickel(II) complex cis-Ni{2-Ph₂PC₆H₄NC(O)CH₂NHCO₂Bz}₂ (12) was prepared from NiCl₂·6H₂O, 2 equiv. of 2·HH and tBuOK in refluxing CH₃OH. Reaction of the piano-stool complex 5 with tBuOK in CH₃OH gave the chiral-at-metal complex Ir(η⁵-Cp*){2-Ph₂PC₆H₄NC(O)CH₂NCO₂Bz} (14), present in solution as two diastereomers. A single-crystal X-ray diffraction study of 14 confirmed the κ³-P/N/N′-tridentate coordination mode. Under similar conditions the chiral-at-metal ruthenium(II) complex Ru(η⁶-p-cymene){2-Ph₂PC₆H₄NC(O)CH₂NCO₂Bz} (15) was prepared in which 2^2– functions efficiently as a dianionic tridentate ligand. All new compounds have been characterised by multinuclear NMR [³¹P{¹H}, ¹H], FT-IR, EI-MS, ES-MS and microanalysis. Furthermore, the X-ray structures of ten compounds have been determined and reveal, in the majority of cases, a strong propensity for the –NHC(O)CH₂NHCO₂Bz group to engage in N–H···N, N–H···O and N–H···Cl hydrogen bonding.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Coordination Studies of a New Nonsymmetric Ditertiary Phosphane Bearing a Single Phosphaadamantane Cage

Co-reporter:Tom J. Cunningham;Mark R. J. Elsegood;Paul F. Kelly, ;Paul M. Stanil

European Journal of Inorganic Chemistry 2008 Volume 2008( Issue 14) pp:2326-2335

Publication Date(Web):

DOI:10.1002/ejic.200800059

Abstract

The new nonsymmetric ditertiary phosphane, Ph₂P(CH₂)₂PAd (1), was prepared in one-step from Ph₂PCH=CH₂ andH-PAd (H-PAd = 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantane) by a hydrophosphination reaction using 2,2′-azo-bisisobutyronitrile (AIBN) as free radical initiator. The sterically encumbered phosphaadamantane cage in 1 was found to influence the coordination capabilities of this ligand. The reaction of 1 with [PdCl₂(cod)] or [Pt(CH₃)₂(cod)] (cod = cycloocta-1,5-diene) gave the corresponding κ²-P,P′-chelate complexes cis-[PdCl₂(1)] (2) and cis-[Pt(CH₃)₂(1)] (3), respectively. The dinuclear gold(I) complex [Ph₂P(AuCl)(CH₂)₂PAd(AuCl)] (4) was prepared from 1 and 2 equiv. of [AuCl(tht)] (tht = tetrahydrothiophene). In contrast, the cleavage of the chloro-bridged dimers {RuCl₂(η⁶-p-cymene)}₂ or {MCl₂(η⁵-Cp*)}₂ (M = Rh, Ir) with 1 gave the κ¹-P-monodentate complexes [RuCl₂(η⁶-p-cymene)(1)] (5), [RhCl₂(η⁵-Cp*)(1)] (6) and [IrCl₂(η⁵-Cp*)(1)] (7), respectively, in which the -PAd group is non-coordinating. Chloride abstraction from 6 (or 7) can be accomplished upon addition of Na[SbF₆] to generate the cationic κ²-P,P′-chelate complexes 8b (and 9b). Alternatively 8a (or 9a) could be observed, as their chloride salts, by ³¹P{¹H} NMR spectroscopy upon addition of several drops of CH₃OH to CDCl₃ solutions of 6 (or 7). The reaction of 5–7 with [AuCl(tht)] gave the dinuclear complexes [κ²-P,P′-μ-RuCl₂(η⁶-p-cymene){Ph₂P(CH₂)₂PAd(AuCl)}] (10), [κ²-P,P′-μ-RhCl₂(η⁵-Cp*){Ph₂P(CH₂)₂PAd(AuCl)}] (11) and [κ²-P,P′-μ-IrCl₂(η⁵-Cp*){Ph₂P(CH₂)₂PAd(AuCl)}] (12). Reaction of two equiv. of 5 with the labile precursors [PdCl₂(CH₃CN)₂] or [PtCl₂(PhCN)₂] gave instead the novel trinuclear Ru₂Pd and Ru₂Pt complexes trans-[{κ²-P,P′-μ-RuCl₂(η⁶-p-cymene){Ph₂P(CH₂)₂PAd}}₂PdCl₂] (13) and trans-[{κ²-P,P′-μ-RuCl₂(η⁶-p-cymene){Ph₂P(CH₂)₂PAd}}₂PtCl₂] (14), respectively. All new compounds have been fully characterised by spectroscopic and analytical methods. Furthermore the structures of 3·CHCl₃, 4, 5, 7·CHCl₃, 10·CH₂Cl₂·0.5C₂H₁₀O and 13·2CH₂Cl₂ have been elucidated by single-crystal X-ray crystallography. The X-ray structures of 10·CH₂Cl₂·0.5C₄H₁₀O and 13·2CH₂Cl₂ demonstrate how nonsymmetric ditertiary phosphane complexes bearing one pendant phosphaadamantane moiety can be used as metalloligands in the controlled syntheses of novel bi- and trimetallic complexes.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

Mononuclear and Heterodinuclear Metal Complexes of Nonsymmetric Ditertiary Phosphanes Derived from R2PCH2OH

Co-reporter:Gavin M. Brown;Mark R. J. Elsegood;Andrew J. Lake;Noelia M. Sanchez-Ballester;Thomas S. Varley;Kevin Blann

European Journal of Inorganic Chemistry 2007 Volume 2007(Issue 10) pp:

Publication Date(Web):23 FEB 2007

DOI:10.1002/ejic.200601199

The new nonsymmetric ditertiary phosphanes, Ph₂PCH₂N(R)CH₂PAd [3a: R = C₆H₅, 3b: R = C₆H₄(4-CH₃)] were prepared using a three-step sequence of condensation reactions. Hence treatment of AdP-H (AdP-H = 1,3,5,7-tetramethyl-2,4,8-trioxa-6-phosphaadamantane) with (CH₂O)_n at 110 °C gave the adamantane-derived hydroxymethylphosphane 1, which upon condensation with C₆H₅NH₂ or C₆H₄(4-CH₃)NH₂ gave the secondary aminophosphanes HN(R)CH₂PAd [2a: R = C₆H₅, 2b: R = C₆H₄(4-CH₃)]. Further condensation of 2a or 2b with Ph₂PCH₂OH gave 3a or 3b in high yields (ca. 85 %) containing the sterically encumbered adamantane cage. The coordination capabilities of 2a, 3a and 3b have been explored with various Pd^II, Pt^II, Ru^II, Ir^III and Au^I metal centres. Bridge cleavage of {Pd(κ²-C,N-C₁₆H₁₆N)Br}₂ with 2 equiv. of 2a gave the neutral, mononuclear complex Pd(κ²-C,N-C₁₆H₁₆N)Br(2a) (4). Reaction of 3a/3b with MCl₂(cod) (M = Pt, Pd) gave the corresponding κ²-P,P′-chelate complexes cis-MCl₂(3) [5a: M = Pt, R = C₆H₅, 5b: Pt, R = C₆H₄(4-CH₃), 5c: Pd, R = C₆H₅, 5d: Pd, R = C₆H₄(4-CH₃)]. In contrast, bridge cleavage of the dimers {RuCl₂(η⁶-p-cym)}₂ or {IrCl₂(η⁵-Cp*)}₂ with 3a gave the κ¹-P-monodentate complexes RuCl₂(η⁶-p-cym)(3a) (6) and IrCl₂(η⁵-Cp*)(3a) (7), respectively, in which the –PAd group is noncoordinating. Reaction of 6 or 7 with AuCl(tht) (tht = tetrahydrothiophene) gave the mixed-metal complexes κ²-P,P′-μ-RuCl₂(η⁶-p-cym){Ph₂PCH₂N(Ph)CH₂PAd(AuCl)} (8) and κ²-P,P′-μ-IrCl₂(η⁵-Cp*){Ph₂PCH₂N(Ph)CH₂PAd(AuCl)} (9). All new compounds have been fully characterised by spectroscopic and analytical methods. Furthermore, the structures of 2a, 4, 5a, 5b and 6–9 have been elucidated by single-crystal X-ray crystallography. The X-ray structures of 5a, 5b and 6–9 represent the first examples of crystallographically characterised nonsymmetric ditertiary phosphane complexes bearing one adamantane moiety. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

New complexes of functionalised ligands bearing P/N/Se or P2Se donor sets

Co-reporter:Sean E. Durran, Mark R. J. Elsegood and Martin B. Smith

New Journal of Chemistry 2002 vol. 26(Issue 10) pp:1402-1408

Publication Date(Web):05 Sep 2002

DOI:10.1039/B204005K

The new selenoether functionalised tertiary phosphines (2-Ph2P)C6H4C(H)N(CH2)nSePh (n=3 1a; 4 1b) were readily prepared by condensation of (2-Ph2P)C6H4C(H)O and H2N(CH2)nSePh (n=3, 4) in absolute ethanol. Reaction of two equiv. of Ph2PCH2OH with H2N(CH2)nSePh (n=3, 4) affords the symmetrical ditertiary phosphines (Ph2PCH2)2N(CH2)nSePh (n=3 2a; 4 2b). Reaction of 1a–2b with [MCl2(cod)] (M=Pt, Pd) gave the dichlorometal(II) chelate complexes 3a–4d in which either six-membered P,P- or P,N-ligation is observed. Chloro bridge cleavage of [{RuCl2(p-cymene)}2] or tht (tht=tetrahydrothiophene) substitution of [AuCl(tht)] with 2a (or 2b) gave the new complexes [{RuCl2(p-cymene)}2{μ-(P,P′-Ph2PCH2)2N(CH2)nSePh}] (n=3 5a; 4 5b) or [{AuCl}2{μ-(P,P′-Ph2PCH2)2N(CH2)nSePh}] (n=3 6a; 4 6b) in which the ligand P,P′-bridges two metal centres. Spectroscopic evidence suggests the pendant selenoether group in 3c undergoes further reaction with [PdCl2(MeCN)2] affording an unusual trinuclear palladium(II) complex 7. Furthermore reaction of 3b with 1 equiv. of Ag[BF4] in dichloromethane gave the cationic complex [PtCl(1a)][BF4] 8 in which 1a functions as a P,N,Se-tridentate ligand. All structures have been confirmed by a combination of spectroscopic, analytical and single crystal X-ray studies. The structure of 8 represents, to the best of our knowledge, an extremely rare example of a crystallographically characterised Group 10 metal complex with a P/N/Se/Cl coordination environment.

Late transition metal complexes of a new P–N ligand Ph2PCH2N(H)C5H3(Cl-5)N: synthesis and structural studies

Co-reporter:Simon J. Coles, Sean E. Durran, Michael B. Hursthouse, Alexandra M. Z. Slawin and Martin B. Smith

New Journal of Chemistry 2001 vol. 25(Issue 3) pp:416-422

Publication Date(Web):22 Feb 2001

DOI:10.1039/B008502M

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.

The synthesis and co-ordination chemistry of new functionalised pyridylphosphines derived from Ph2PCH2OH

Co-reporter:Sean E. Durran, Martin B. Smith, Alexandra M. Z. Slawin and Jonathan W. Steed

Dalton Transactions 2000 (Issue 16) pp:2771-2778

Publication Date(Web):27 Jul 2000

DOI:10.1039/B003759L

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.

Molybdenum(0), ruthenium(II), palladium(II), platinum(II), copper(I) and gold(I) complexes of a new methoxy functionalised bis(phosphino)amine: synthesis and structure

Co-reporter:Kirsty G. Gaw, Martin B. Smith and Alexandra M. Z. Slawin

New Journal of Chemistry 2000 vol. 24(Issue 6) pp:429-435

Publication Date(Web):22 May 2000

DOI:10.1039/B001458N

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.

Synthesis and characterisation of E,O-mixed donor (E=P, S or Se) ligand complexes of palladium(II) and platinum(II)

Co-reporter:Martin B Smith, Alexandra M.Z Slawin

Inorganica Chimica Acta 2000 Volume 299(Issue 2) pp:172-179

Publication Date(Web):15 March 2000

DOI:10.1016/S0020-1693(99)00493-4

New palladium(II) and platinum(II) complexes with the hybrid ligands Ph2PNHP(O)Ph2, [Ph2PNP(O)Ph2]− or [Ph2P(E)NP(O)Ph2]− (E=S or Se) have been prepared and characterised. Hence reaction of the cyclometallated dimers [{Pd(μ-Cl)(C∼N)}2] [C∼N=C12H9N2 or C13H8N] with Ph2PNHP(O)Ph2 gave the mononuclear compounds [PdCl(C∼N){Ph2PNHP(O)Ph2-P}]. Chloride abstraction, or amine deprotonation, afforded [Pd(C∼N){Ph2PNHP(O)Ph2-P,O}][BF4] or [Pd(C∼N){Ph2PNP(O)Ph2-P,O}] bearing a neutral or anionic P,O-chelating ligand, respectively. Reaction of [{Pd(μ-Cl)(C9H12N)}2] with Ph2PNHP(O)Ph2 in CDCl3 solution gave the known, rather unstable compound, [PdCl(C9H12N){Ph2PNHP(O)Ph2-P}]. Spectroscopic and analytical evidence presented here suggest that [PdCl(C9H12N){Ph2PNHP(O)Ph2-P}] undergoes amine deprotonation/PdC bond rupture to give an isomeric compound, tentatively assigned as [PdCl{Ph2PNP(O)Ph2-P,O}(NMe2CH2Ph)]. Bridge cleavage of [{Pd(μ-Cl)(C12H9N2)}2] with the unsymmetrical anions [Ph2P(E)NP(O)Ph2]− (E=S or Se) gave the square–planar complexes [Pd(C12H9N2){Ph2P(E)NP(O)Ph2-E,O}] exclusively as one isomer (E trans to N). In a similar manner the new metal(II) compounds [PtCl{Ph2P(E)NP(O)Ph2-E,O}(PMe2Ph)] (E trans to Cl) and [Pd(C9H15O){Ph2P(E)NP(O)Ph2-E,O}] (E trans to olefin double bond) were synthesised. All compounds were characterised by a combination of multinuclear NMR [1H, 31P{1H}, 195Pt{1H}], IR spectroscopy and elemental analyses. Furthermore, the X-ray structures of [Pd(C12H12N){Ph2PNHP(O)Ph2-P,O}][BF4] and [Pd(C12H12N){Ph2PNP(O)Ph2-P,O}] are reported and reveal, upon amine deprotonation, π-delocalisation within the PNPO backbone of the anionic P,O-chelating ligand.

A novel fluorene-containing κ4-P2N2-tetradentate platinum(II) complex

Co-reporter:Mark R. J. Elsegood, Andrew J. Lake and Martin B. Smith

Dalton Transactions 2009(Issue 1) pp:NaN32-32

Publication Date(Web):2008/11/17

DOI:10.1039/B816351K

Flexible κ4-PNN′O-tetradentate ligands: synthesis, complexation and structural studies

Co-reporter:Sean E. Durran, Mark R. J. Elsegood, Shelly R. Hammond and Martin B. Smith

Dalton Transactions 2010 - vol. 39(Issue 30) pp:NaN7146-7146

Publication Date(Web):2010/06/24

DOI:10.1039/C0DT00200C

Versatile routes to selenoether functionalised tertiary phosphines

Co-reporter:Tom J. Cunningham, Mark R. J. Elsegood, Paul F. Kelly, Martin B. Smith and Paul M. Staniland