Lesley J. S. Prouse

Metal complexes of functionalized phosphines—II. Synthesis of hydroxymethyl- and aminomethyldiphenylphosphine complexes of platinum. Crystal structure of cis-[PtCl2(Ph2PCH2OH)2] ☆

The phosphine Ph 2 PCH 2 OH reacts with (COD)PtCl 2 to form cis -PtCl 2 (Ph 2 PCH 2 OH) 2 ], the structure of which has been determined by X-ray crystallography. Similarly, the phosphines Ph 2 PCH 2 NHR (R = Bu t , C 6 H 4 Me-4) react with (COD)PtCl 2 to form cis -[PtCl 2 (Ph 2 PCH 2 NHR) 2 ], although for R = C 6 H 4 Me-4 this complex is unstable and [PtCl 2 {(Ph 2 PCH 2 ) 2 NR}] (R = C 6 H 4 Me-4) is isolated. The complexes [PtCl 2 {Ph 2 PCH 2 ) 2 NR}] can be prepared directly from (COD)PtCl 2 and (Ph 2 PCH 2 ) 2 NR.

Isomeric forms of tris-Schiff base complexes of iron(II) : structure of the complex derived from 2-acetyl pyridine and methylamine

SummaryThe structure of the tetrahydrate of the nitroprusside salt of the tris-ligand-FeII complex of the Schiff base derived from 2-acetyl pyridine and methylamine has been established by x-ray diffraction methods. The cation has themer-configuration in this salt in the solid phase. Kinetic and spectroscopic, particularly1H n.m.r., results indicate that bothmer-andfac-isomers of this, and of related complexes, have to be considered in solution. Kinetics of base hydrolysis of the title cation, and its solvation, in MeOH-H2O mixtures are described and compared with those for other low-spin FeII-diimine complexes.

Metal complexes of functionalized phosphines-I. Synthesis and characterization of 2-diphenylphosphinoethylamines and some of their complexes with platinum. X-ray structure of [HBut)(Ph2PCH2CH2NHBut·HCl)Cl]Cl·H2O

Abstract The new bidentate ligands Ph 2 PCH 2 CH 2 NHR [R = Bu t , CH 2 Ph, CH(Me)Ph] and Ph 2 PCH 2 CH 2 N(CH 2 Ph) 2 and their corresponding hydrochloride salts have been synthesized and were characterized by 1 H, 31 P-{ 1 H} and 13 C-{ 1 H} NMR spectroscopy. The ligand Ph 2 PCH 2 CH 2 NHBu t reacts with K 2 PtCl 4 or (COD)PtCl 2 to form [P t (Ph 2 PCH 2 CH 2 NHBu t ) (Ph 2 PCH 2 CH 2 NHBu t ·HCl)Cl]Cl, whose structure has been determined by X-ray diffraction. Treatment of this complex with HCl gas gives [Pt(Ph 2 PCH 2 CH 2 NHBu t ·HCl) 2 Cl 2 ] which can also be synthesized from Ph 2 PCH 2 CH 2 NHBu t ·HCl and K 2 PtCl 4 .

Chemistry of metallacyclobutanones (η3-oxodimethylenemethane complexes). Part 5. Ligand substitution reactions of metallacyclobutan-3-ones of platinum(II) and palladium(II) with tertiary phosphines and t-butyl isocyanide; crystal structures of [Pt{CH(CO2Me)COCH(CO2Me)}(CNBut)(AsPh3)] and [Pt{CH(CO2Me)CO(CO2Me)C(NHBut)}(CNBut)2]

The ligands L displace triphenylarsine from the complexes [[graphic omitted]H(CO2Me)}(AsPh3)2] to give good yields of the complexes [[graphic omitted]H(CO2Me)}L2](M = Pt, L = PPh3, PMePh2, PMe2Ph, L2= Ph2PCH2CH2PPh2(dppe); M = Pd, L = PPh3, L2= 2,2′-bipyridine). Treatment of the complexes [[graphic omitted]H(CO2Me)}L2] with one mole equivalent of t-butyl isocyanide gives the monosubstituted complexes [[graphic omitted]H(CO2Me)}(CNBut)L](M = Pt or Pd, L = AsPh3 or PPh3). The single-crystal X-ray structure of [[graphic omitted]H(CO2Me)}(CNBut)(AsPh3)] establishes the presence of a puckered platinacyclobutan-3-one ring [fold angle = 42(1)°] with the triphenylarsine ligand trans to the axial methoxycarbonyl group. The reactions of 1 mole equivalent of t-butyl isocyanide with [[graphic omitted]H(CO2Me)}(CNBut)(PPh3)] or 2 mole equivalents of CNBut with [[graphic omitted]H(CO2Me)}(PPh3)2] give the ring-expanded zwitterionic complex [[graphic omitted]NHBut}(CNBut)(PPh3)]. Similar complexes [[graphic omitted]NHBut}(CNBut)2] are formed upon treatment of [[graphic omitted]H(COR)L2](R = OMe, L = AsPh3 or PPh3; R = Me, L = PPh3) with three mole equivalents of CNBut. The structure of [[graphic omitted]NHBut}(CNBut)2] was established by a single-crystal X-ray diffraction study.

Metallacyclic complexes. Part 3. Reactions of metallathietane 3,3-dioxide complexes of platinum(II) and palladium(II) with alkyl isocyanides; the single crystal X-ray structure of [Pt{CH(COPh)S(O)2C(COPh)CNHBun}(CNBut)-(PPh3)]·CHCl3

The reactions of the metallathietane 3,3-dioxide complexes [[graphic omitted]HR}L2] of platinum(II) and palladium(II) with alkyl isocyanides are dependent on both the mole ratio of isocyanide to metal complex, and on the ring substituent R. Treatment of phenyl-substituted metallathietane 3,3-dioxide complexes with excess of isocyanide results in ligand substitution to afford monosubstituted complexes of the type [[graphic omitted]HPh}(CNBut) L]. Similarly, treatment of the benzoyl-substituted complexes [[graphic omitted]H(COPh)}L2] with 1 equivalent of isocyanide also affords monosubstituted complexes [[graphic omitted]H(COPh)}(CNR)L](M = Pt, L = PPh3, R = Bun or But; M = Pd, L = PEt3, R = But). On treatment of platinathietane 3,3-dioxide complexes containing benzoyl or methoxycarbonyl ring substituents with excess of isocyanide, ring insertion and hydrogen migration occurs to afford the zwitterionic five-membered ring products [[graphic omitted]NHR′}(CNR′)L] (L = PPh3 or PMe2Ph; R = COPh or CO2Me; R′ = But or Bun). Treatment of [[graphic omitted]H(COPh)}(PPh3)(CNBut)] with 1 equivalent of BunNC, or [[graphic omitted]H(COPh)}(CNBun)(PPh3)] with 1 equivalent of ButNC, affords, in both cases, the n-butyl isocyanide-inserted product [[graphic omitted]NHBun}(CNBut)(PPh3)] (13), confirmed by a single-crystal X-ray diffraction study carried out on (13)·CHCl3. Crystals are monoclinic, space group P21/n, Z = 4, in a unit cell with lattice parameters a = 28.337(2), b = 9.625(2), c = 16.507(1) A, and β = 101.71 (5)°. The structure was refined to R 0.0661 (R′ 0.0530) for 4 019 reflections having 7 < 2θ < 54° collected at room temperature.

Metallacyclic complexes. Part 4. Synthesis of platinathietane-3-oxide complexes, and the single-crystal X-ray structure of [Pt{CH(COPh)S(O)CH(COPh)}(PPh3)2]·2CH2Cl2

Treatment of the complexes cis-[PtCl2L2] with diphenacyl sulphoxide, (PhCOCH2)2SO, and an excess of silver(I) oxide in refluxing dichloromethane affords high yields of the platinathietane-3-oxide complexes [[graphic omitted]H(COPh)}L2](L = PPh3, PMePh2, or PMe2Ph). A single-crystal X-ray diffraction study has been carried out on [[graphic omitted]H(COPh)}(PPh3)2](6a)·2CH2Cl2. The crystals are triclinic, space group P, Z= 2, in a unit cell with a= 13.824(1), b= 12.953(2), c= 19.248(6)A, α= 118.0(2), β= 52.4(2), and γ= 113.56(5)°. The structure has been refined to R 0.0487 (R′ 0.0512) for 7 864 reflections with (I) 3σ(I). The complex contains a puckered platinathietane-3-oxide ring [fold angle 36.65(46)°] with the sulphinyl oxygen in the expected equatorial environment. The presence of short carbon–sulphur bonds is interpreted in terms of a contribution from a heteroallylic bonding representation. Room-temperature 1H n.m.r. spectra for the platinathietane-3-oxide complexes indicate that the four-membered rings are puckered and non-fluxional in solution. The magnitude of the platinum-195 coupling to the axial and equatorial ring hydrogens of the platinathietane-3-oxide ring is dependent upon the orientation of the CH bonds with respect to the square-planar platinum function and the magnitudes of 3J(cis-PPtCH) are dihedral angle controlled. The reaction of [Pt2Br4(PEt3)2] with 1 equivalent of triphenylarsine and diphenacyl sulphoxide per platinum and an excess of silver(I) oxide in refluxing dichloromethane affords the mixed-ligand complex [[graphic omitted]H(COPh)}(AsPh3)(PEt3)], which exists as a mixture of two isomers, the major (76%) isomer having the triphenylarsine ligand trans to an axial COPh substituent.

Metallacyclic complexes. Part 2. Synthesis of metallathietane-3,3-dioxide complexes of platinum(II) and palladium(II); the crystal structures of [Pt{CH(COPh)S(O)2CH(COPh)}(PPh3)2]·2CH2CI2 and [Pd{CH(COPh)S(O)2CH(COPh)}(PMePh2)2]·CH2Cl2·H2O

The reactions of the complexes cis-[PtCl2L2] or trans-[PdCl2L2](L = tertiary phosphine or triphenyl phosphite) with bis(benzoylmethyl) sulphone or the dimethyl ester of 2,2′-sulphonyldiacetic acid and an excess of silver(II) oxide in refluxing dichloromethane afford, in high yields, the metallathietane-3,3-dioxide complexes [[graphic omitted]H(COR)}L2](R = Ph, M = Pt or Pd, L = PPh3, PMePh2, PMe2Ph, PMe3, PEt3, or PBun3; M = Pt, L = P(OPh)3; R = OMe, M = Pt or Pd, L = PPh3). Single-crystal X-ray diffraction studies have been carried out on [[graphic omitted]H(COPh)}(PPh3)2]·2CH2Cl2, [(6a)] and [[graphic omitted]H(COPh)}(PMePh2)2]·CH2Cl2·H2O [(6i)]. Crystals of (6a)·2CH2Cl2, are triclinic, space group P, Z= 2, in a unit cell with lattice parameters a= 20.835(2), b= 10.628(2), c= 12.577(4)A, α= 109.6(1), β= 105.8(1), and γ= 91.4(l)°. The structure was refined to R 0.0595 (R′ 0.0580) for 5 553 reflections having 7 < 2θ < 54°(Mo-KαX-radiation) collected at room temperature. Crystals of (6i)·CH2Cl2·H2O are triclinic, space group P, Z= 2, in a unit cell with lattice parameters a= 12.985(5), b= 13.93(1), c= 12.057(6)A, α= 73.71(3), β= 102.61(5), and γ= 100.01 (3)°. The structure was refined to R 0.0745 (R′ 0.0823) for 5 536 reflections having 7 < 2θ < 54° collected at room temperature. Both molecules contain a puckered metallathietane-3,3-dioxide ring [fold angles 15.3(6) for (6a) and 30.2(2)° for (6i)]. The puckering of the four-membered rings, together with the presence of short C–S bonds suggests a heteroallylic contribution to the metallacyclic bonding. N.m.r. data for the metallathietane-3,3-dioxide complexes are also reported.

Chemistry of metallacyclobutanones. Part 4. The synthesis of 1,3-diphenyl-substituted oxodimethylenemethane complexes of platinum(II) and palladium(II)via the dianion [PhCHC(O)CHPh]2–, and the X-ray crystal structure of [Pt{η3-CHPhC(O)CHPh}(AsPh3)2]·2CH2Cl2

Treatment of the complexes cis-[PtCl2L2] or trans-[PdCl2L2] with the organopotassium reagent K2[PhCHC(O)CHPh] in tetrahydrofuran affords the η3-oxodimethylenemethane (puckered metallacyclobutan-3-one) complexes [M{η3-CHPhC(O)CHPh}L2](M = Pt, L = AsPh3 or PPh3; L2= cyclo-octa-1,5-diene (cod); M = Pd, L = PPh3 or PEt3). X-Ray data indicate that these complexes contain highly non-planar metal–oxodimethylenemethane systems with both phenyl substituents adopting equatorial positions. In the synthesis of [Pt{η3-CHPhC(O)CHPh}(PPh3)2] a small amount of a trans diphenyl-substituted isomer is formed, along with the principal cis diequatorial isomer. N.m.r. data for the oxodimethylenemethane complexes are reported.

The preparation and structures of metallathietane-3-oxides and –3,3-dioxides of platinum and palladium: the crystal structures of trans-2,4-dibenzoyl-1,1-bis(triphenylphosphine)platinathietane-3-oxide and trans-2,4-dibenzoyl-1,1-bis(triphenylphosphine)platinathietane-3,3-dioxide

High yields of platinathietane-3-oxides and metallathietane-3,3-dioxides may be obtained by treatment of [MCl2L2] with [RCH2S(O)nCH2R](n= 1, R = COPh; n= 2, R = COPh or CO2Me) and silver(I) oxide; single crystal X-ray studies on the title complexes establish the presence of puckered metallacycles, the sulphinyl oxygen of the platinathietane-3-oxide adopting an equatorial environment.