Elisa Hernández

Thiolate derivatives of bis(diphenylphosphinocyclopentadienyl)titanium TiPt and TiPd heterobimetallic compounds

Abstract Reactions of [ ν 5 -C 5 H 4 P(C 6 H 5 ) 2 2 TiCl 2 ] with HSR in the presence of Et 3 N gave the new compounds ν 5 -C 5 H 4 P(C 6 H 5 ) 2 2 Ti(SR) 2 ] (R = CH 2 C 6 H 5 ( 1 ), C 6 H 5 ( 2 ), CH 2 CH 3 ( 3 ), C 6 F 5 ( 4 ) and [ ν 5 -C 5 H 4 P(C 6 H 52 )2TiCl(SC 6 H 11 )] ( 5 ). The complex [ ν 5 C 5 H 4 P(C 6 H 5 ) 2 ) 2 Ti(SC 6 F 5 ) 2 ] can be prepared in higher yield by reaction of TISC 6 F 5 with [ ν 5 -C 5 H 4 P(C 6 H 5 ) 2 2 TiCl 2 ] in toluene. These compounds are of interest as metalloligands to form bimetallic and trimetallic species. The treatment of [ ν 5 -C 5 H 4 P(C 6 H 5 ) 2 TiCl 2 ] or [ ν 5 -C 5 H 4 P(C 6 H 5 ) 2 Ti(SC 6 H 5 ) 2 ] with cis -[M(C 6 F 5 ) 2 (THF) 2 ] gave the new heterobimetallic complexes [Cl 2 Ti μ -C 5 H 4 P(C 6 H 5 ) 2 2 M(C 6 F 5 ) 2 ] [M=Pt ( 6 ) or Pd ( 7 )] and [(C 6 H 5 S) 2 Ti μ -C 5 H 4 P(C 6 H 5 ) 2 2 Pt(C 6 F 5 )2] ( 8 ). In all cases the THF of the cis -[M(C 6 F 5 ) (THF) 2 ] was easily replaced by the phosphine rather than chloride or thiolate. The compounds have been characterized by 1 H, 31 P and 19 F NMR spectroscopies and FAB mass spectrometry.

Reactivity of Fe3(CO)12 towards thiols containing an α,β-unsaturated ketone system

Abstract The unsaturated derivatives [Fe 2 (CO) 6 (μ-S 2 CCHC(O)C 6 H 4 X)] (X=F, OMe) have been isolated by reaction of [(HS) 2 CCHC(O)C 6 H 4 X] (X=F, OMe) with Fe 3 (CO) 12 in dried THF. Addition of Fe 2 (CO) 9 to a solution of [Fe 2 (CO) 6 (μ-S 2 CCHC(O)C 6 H 4 OMe)] affords [Fe(CO) 4 {μ-(OMe)C 6 H 4 C(O)CHC(S) 2 Fe 2 (CO) 6 }]. The new compounds have been characterised by analytical and spectroscopic data and the crystal structure of [Fe 2 (CO) 6 (μ-S 2 CCHC(O)C 6 H 4 F)] has been solved by X-ray diffraction.

A comparative study of the use of triethylammonium salts of the [Fe2(CO)6(μ-CO)(μ-SR)]− anion in the synthesis of iron-gold clusters. Crystal structures of [Fe2(CO)6(μ-CO)(μ-SiPr)(μ-AuPPh3)] and [Fe2(CO)5(PPh3)(μ-SEt)2]

Abstract Salts of the type (NEt3H)[Fe2(CO)6(μ-CO)(μ-SR)] (R=1cr; iPr, tBu, Ph) react with [ClAuPPh3] in the presence of TIBF4 to produce the neutral iron-gold clusters [Fe2(CO)6(μ-CO)(μ-SR)(μ-AuPPh3)] (R=1cr; iPr, 1; R=1cr; tBu, 2; R=1cr; Ph, 3) in high yields. The structure of 1 has been determined by X-ray diffraction methods. Crystals are monoclinic, space group P21/c, with a = 11.373(1), b = 14.899(3), c = 17.997(8) A, β = 95.12(2)° and Z = 4, R = 0.030 and R′ = 0.035 for 3579 unique reflections with I ⩾ 2σ(I). The basic skeleton consists of an Fe2Au triangle where the FeFe bond is bridged by a carbonyl and a thiolate group. In contrast, the reaction of the salts (NEt3H)[Fe2(CO)6(μ-CO)(μ-SR)] (R = Et or C6F5) with [ClAuPPh3] does not afford the corresponding mixed iron-gold clusters, and the diiron mono- or di-substituted complexes [Fe2(CO)5 (PPh3)(μ-SR)2] (R=1cr; Et, 4; R=1cr; C6F5, 5) and [Fe2(CO)4(PPh3)2(μ-SEt)2] (6) are obtained instead. The structure of 4 has been established by single-crystal X-ray diffraction studies. Crystals are triclinic, space group, P 1 , with a = 10.472(4), b = 11.329(2), c = 13.437(2) A, α = 80.34(2), β = 92.62(3), γ = 114.46(2)°, and Z = 2, R = 0.027 and R′ = 0.030 for 3732 unique reflections with I ⩾ 2σ(I). The FeFe bond in 4 is almost symmetrically double-bridged by two thiolate ligands and the phosphine group attached to the Fe(1) is trans to the iron-iron bond.

Novel heterobimetallic titanium–platinum complexes. Crystal structure of [(η5-C5H4SiMe3)(SPh)Ti(μ,η5-κS-C5H4P(S)Ph2)(μ-SPh)Pt(C6F5)2]

Abstract The thiophosphorylcyclopentadienyl-thiolate complexes [(η5-C5H4R)(η5-C5H4P(S)Ph2)Ti(SPh)2] react with cis-[Pt(C6F5)2(THF)2] initially give the adducts [(η5-C5H4R)(SPh)Ti(μ,η5-κS-C5H4P(S)Ph2)(μ-SPh)Pt(C6F5)2] [R=P(S)Ph2 (1); SiMe3 (4)], which finally rearrange in solution to form the double thiolate-bridged derivatives [(η5-C5H4R)(η5-C5H4P(S)Ph2)Ti(μ-SPh)2Pt(C6F5)2] [R=P(S)Ph2 (2) (syn); SiMe3 (5) (syn/anti)]. This paper presents the crystal structure of 4, a complex displaying an unusual mixed thiolate-thiophosphorylcyclopentadienyl bridging system. In contrast, similar reactions of cis-[Pt(C6F5)2(THF)2] with [(η5-C5H4R)(η5-C5H4P(O)Ph2)Ti(SPh)2] (R=P(O)Ph2; SiMe3) only gives [(η5-C5H4R)(η5-C5H4P(O)Ph2)Ti(μ-SPh)2Pt(C6F5)2] [R=P(O)Ph2 (3) (syn); SiMe3 (6) (syn/anti mixtures)] as expected due to the soft acid nature of the platinum centre.

Iron carbonyls with bulky thiolate ligands: crystal structures of [Fe2(CO)6(μ-SC6H2-2,4,6)2] and (C6H2-2,4,6)2S2

Abstract The reaction of Fe3(CO)12 and bulky thiols HSR (R = C6H2 i Pr 3 -2,4,6; C6H2Me3-2,4,6) in toluene yielded compounds [Fe2(CO)6(μ-SR)2] (R = C6H2 i Pr 3-2,4,6 (1), C6H2Me3-2,4,6 (2)). The substitution of one carbonyl by the phosphine Ph2P(CH2)2Si(OEt)3 in complex 1 afforded {Fe2(CO)5[Ph2P(CH2)2Si(OEt)3](μ-SC6H2 i Pr 3-2,4,6)2} (3). Mononuclear compounds [(η5-C5H5)Fe(CO)2(SC6H2 i Pr 3 -2,4,6)] (4) and {(η5-C5H5)Fe(CO)[Ph2P(CH2)2Si(OEt)3](SC6H2 i Pr 3 -2,4,6)} (5) have also been obtained. Compound 1 has been studied by X-ray diffraction and the structure determined reveals a distorted octahedron geometry around each iron atom and confirms the anti arrangement of R substituents, R = C6H2 i Pr 3 -2,4,6, in the molecule. The preparation of thiol HSC6H2 i Pr 3 -2,4,6 yielded the disulfide (C6H2 i Pr 3 -2,4,6)2S2 as a by-product, whose structure has been solved by X-ray diffraction.

Synthesis of heteronuclear compounds by use of [Ti(η5-C5H4PPh2)2(SR)2](R = Et or Ph) as metalloligands. Crystal structures of [{Mo(CO)4}2{µ-(Ph2PC5H4)2Ti(SPh)2}] and [(OC)4Mo(µ-Ph2PC5H4)2Ti(µ-SPh)2Pt(C6 F5)2]

The complexes [(OC)4Mo(µ-Ph2PC5H4)2Ti(SR)2](R = Et 1 or Ph 2), [{Mo(CO)4}2{µ-(Ph2PC5H4)2Ti(SR)2}](R = Et 3 or Ph 4) and [(OC)4Mo(µ-Ph2PC5H4)2Ti(µ-SPh)2M(C6F5)2](M = Pt 5 or Pd 6) have been prepared and characterized. Complexes 1 and 2 were obtained by reaction of [Ti(η5-C5H4PPh2)2(SR)2] and [Mo(CO)4(nbd)](nbd = norbornadiene) in 1 : 1 molar ratio by replacement of the nbd by two cyclopentadienyldiphenylphosphines co-ordinated by the P atoms. The ability of the S atoms in the thiolate ligands to act as Lewis bases leads to a further increase in nuclearity. Thus, when the reaction was carried out in a 1 : 3 molar ratio, heterotrinuclear complexes 3 and 4 were obtained. The crystal structure of 4 showed that the titanium mononuclear compound acts as a symmetric S,P-bridging tetradentate ligand towards two Mo(CO)4 fragments. Compound 2 reacted with cis-[M(C6F5)2(thf)2](M = Pt or Pd, thf = tetrahydrofuran) to give 5 and 6, respectively. The crystal structure of 5 showed that 2 acts as an S,S-bidentate metalloligand towards the M(C6F5)2 fragment. It is remarkable that both structures reveal a different co-ordination mode of the tetradentate [Ti(η5-C5H4PPh2)2(SR)2] ligand.

Synthesis of tetrametallic thiolate-bridged Fe3Au clusters. Crystal structure of [Fe3(CO)9(µ3-SPri){µ-Au(PPh3)}]

The reaction of the lithium salt of [Fe3(CO)9(µ3-SR)]– with [Au(PPh3)Cl], in the presence of TIBF4, gives high yields of the new tetrametallic clusters [Fe3(CO)9(µ-SR){µ3-Au(PPh3)}](R = Pri1, But2, C6H113 or Et 4). Clusters 3 and 4 were formed along with the dimetallic species [Fe2(CO)6(µ-CO)(µ-SR){µ-Au(PPh3)}](R = C6H115 or Et 6). The structure of 1 has been determined by X-ray diffraction methods. The metal core consists of an isosceles triangle of iron atoms, capped by a Spri ligand and the longest iron–iron bond is bridged by an Au(PPh3) fragment. The fast atom bombardment mass spectra of the positive ions of 1–4 show a similar pattern to that reported for [Fe3(CO)9(µ3-SR)(µ-H)] consisting of a primary fragmentation involving stepwise loss of carbonyl groups from the parent ion to give [Fe3-(SR){Au(PPh3)}]+, followed by elimination of an olefinic group to give [Fe3(SH){Au(PPh3)}]+ and finally loss of hydrogen to afford [Fe3(S){Au(PPh3)}]+.

Electrical Bistability around Room Temperature in an Unprecedented One-Dimensional Coordination Magnetic Polymer

The synthesis, crystal structure, and physical properties of an unprecedented one-dimensional (1D) coordination polymer containing [Fe2(S2C6H2Cl2)4](2-) entities bridged by dicationic [K2(μ-H2O)2(THF)4](2+) units are described. The magnetic properties show that the title compound presents pairwise Fe-Fe antiferromagnetic interactions that can be well reproduced with a S = 1/2 dimer model with an exchange coupling, J = -23 cm(-1). The electrical conductivity measurements show that the title compound is a semiconductor with an activation energy of about 290 meV and two different transitions, both with large hysteresis of about 60 and 30 K at 260-320 K and 350-380 K, respectively. These two transitions are assumed to be due to slight structural changes in the cation-anion interactions. Differential Scanning Calorimetry confirms the presence of both transitions. This compound represents the first sample of a coordination polymer showing electrical bistability.

Synthesis and characterization of oxo- and thiophosphorylcyclopentadienyl Ti(IV) thiolate complexes. Crystal structures of [(η5-C5H4P(S)Ph2)(η5-C5H4SiMe3)TiCl2] and [(η5-C5H4P(S)Ph2)2Ti(SPh)2]·C4H10O

Abstract New titanium (IV) complexes containing diphenyloxo- or diphenylthiophosphorylcyclopentadienyl ligands are obtained by reaction of diphenylphosphinocyclopentadienyl derivatives with the appropriate oxidizer (S 8 or H 2 O 2 ). The crystal structures of [( η 5 -C 5 H 4 P(S)Ph 2 )( η 5 -C 5 H 4 SiMe 3 )TiCl 2 ] 3 and [( η 5 -C 5 H 4 P(S)Ph 2 ) 2 Ti(SPh) 2 ]·C 4 H 10 O 7 indicate in both cases, a pseudo-tetrahedral arrangement around the titanium atom. The two SPh ligands in compound 7 are orientated in opposite sites of the TiS 2 plane, which suggests an anti conformation for this molecule.

Synthesis and crystal structure of a diplatinum cyclopentadienyldiphenylphosphine sulphide bridged complex

Abstract The mixed early–late TiPt2 compound [(η5-C5H4SiMe3)Ti(μ3-1η5-C5H4P(S)Ph2-2,3κS)(μ-SPh)2{Pt(C6F5)2}2] (3) containing a functionalised thiophosphorylcyclopentadienyl SPPh2C5H4 bridging ligand has been obtained by reaction of [(η5-C5H4SiMe3)(η5-C5H4P(S)Ph2)Ti(SPh)2] (1) with 2 equivalents of cis-[Pt(C6F5)2(thf)2]. The crystallisation of 3 in CH2Cl2/MeOH at −20°C gave the unexpected diplatinum complex [Pt(C6F5)2(μ-SPPh2C5H5)]2 (4) with an unusual double bis-cyclopentadienyldiphosphine sulphide bridging system (μ-κS), which has been characterised by X-ray diffraction. As an alternative route to the synthesis of 4 the reaction of cis-[Pt(C6F5)2(thf)2] with SPPh2C5H5 has been studied. Independently of the stoichiometry employed, this reaction gives mixtures of 4 and the novel mononuclear complex cis-[Pt(C6F5)2(SPPh2C5H5)2] (6). Low temperature control of this reaction indicates that both complexes (4 and 6) are formed through a common intermediate identified as cis-[Pt(C6F5)2(SPPh2C5H5)(thf)] (5) on the basis of spectroscopic techniques.