Crystal structures of phosphomolybdyl salts: Pb(MoO2)2(PO4)2 and Ba(MoO2)2(PO4)2

Crystal structures of Pb(MoO₂)₂(PO₄)₂ and Ba(MoO₂)₂(PO₄)₂ were determined. Both compounds contain the molybdyl group MoO₂. The monoclinic unit-cell parameters are a = 6.353(7), b = 12.289(4), c = 11.800 Å, β = 92°56(6), and Z = 4 for the lead salt and a = 6.383(8), b = 7.142(7), c = 9.953(8) Å, β = 95°46(8), and Z = 2 for the barium salt. $\text{P2}{}_1\text{c}$ is the common space group. The R values are respectively R = 0.027 and R = 0.031 for 1964 and 1714 independent reflections. The frameworks built up by a three-dimensional network of monophosphate PO₄ and molybdyl MoO₂ groups are similar, characterized mainly by corner-sharing PO₄ and MoO₆ polyhedra. Two oxygen atoms of each MoO₆ group are bonded to the molybdenum atom only as in other molybdyl salts.     

Syntheses and structural studies on two cycloruthenapentadienyl complexes: [(CO)3RuC4(CH2OH)4]Ru(CO)3·H2O and [(CO)3RuC4(CH2CH2OH)2(C2H5)2]Ru(CO)3

Syntheses and single-crystal X-ray diffraction studies have been completed on two cycloruthenapentadienyl (CO)₆Ru₂L₂ derivatives, with L = CH₂OHC = CCH₂OH and C₂H₅C=CCH₂CH₂OH respectively. Crystal data are as follows: for [(CO)₃RuC₄(CH₂OH)₄]Ru(CO)₃·H₂O, P2₁/c, a 13.72(1), b 9.501(4), c 14.86(1) Å, β 101.10(6)°, R_w = 0.052 for 1911 reflections; for [(CO)₃RuC₄(CH₂CH₂OH)₂(C₂H₅)₂]Ru(CO)₃, P2₁/c, a 9.191(3), b 16.732(4), c 14.903(3) Å, β 113.61(4)°, R_w = 0.042 for 2865 reflections. Both compounds are built up from binuclear units, each unit being regarded as a Ru(CO)₃ fragment π-bonded to a cycloruthenapentadienyl ring. The molecular parameters are compared with those of known cyclometallapentadienyl complexes of transition metals. The presence of a semi-bridging CO group is discussed.     

Crystal structure of cerium(III) diammonium polyphosphate (NH4)2Ce(PO3)5

Cerium(III) diammonium polyphosphate, (NH₄)₂Ce(PO₃)₅, is triclinic P1 with the following unit cell dimensions: a = 7.241(5) Å, b = 13.314(8) Å, c = 7.241(5)Å, α = 90.35(5)°, β′ = 107.50(5)°, γ = 90.28(5)°, and Z = 2, V = 665.7 ų, D_x = 2.85 g/cm³. The crystal structure of this new type of polyphosphate has been solved and refined from 4130 independent reflections to a final R value 0.029. The most interesting feature of this salt is the existence of two infinite crystallographically nonequivalent (PO₃)^?_∞ chains, one running parallel to the a axis, the other along the c axis, both with a period of five tetrahedra. This compound seems to be the first example of a long chain polyphosphate with crystallographic independent chains.     

Synthesis and characterisation of HRuRh3(CO)12. Crystal structures of HRuRh3(CO)12, HRuRh3(CO)10(PPh3)2 and HRuCo3(CO)10(PPh3)2

A new ruthenium-rhodium mixed-metal cluster HRuRh₃(CO)₁₂ and its derivatives HRuRh₃(CO)₁₀(PPh₃)₂ and HRuCo₃(CO)₁₀(PPh₃)₂ have been synthesized and characterized. The following crystal and molecular structures are reported: HRuRh₃(CO)₁₂: monoclinic, space group P2₁/c, a 9.230(4), b 11.790(5), c 17.124(9) Å, β 91.29(4)°, Z = 4; HRuRh₃(CO)₁₀(PPh₃)₂·C₆H₁₄: triclinic, space group P$\text{1}$, a 11.777(2), b 14.079(2), c 17.010(2) Å, α 86.99(1), β 76.91(1), γ 72.49(1)°, Z = 2; HRuCo₃(CO)₁₀(PPh₃)₂·CH₂Cl₂: triclinic, space group P$\text{1}$, a 11.577(7), b 13.729(7), c 16.777(10) Å, α 81.39(4), β 77.84(5), γ 65.56°, Z = 2. The reaction between Rh(CO)₄^? and (Ru(CO)₃Cl₂)₂ tetrahydrofuran followed by acid treatment yields HRuRh₃(CO)₁₂ in high yield. Its structural analysis was complicated by a 80–20% packing disorder. More detailed structural data were obtained from the fully ordered structure of HRuRh₃(CO)₁₀(PPh₃)₂, which is closely related to HRuCo₃(CO)₁₀(PPh₃)₂ and HFeCo₃(CO)₁₀(PPh₃)₂. The phosphines are axially coordinated.     

A dichromium(II) compound with an elongated metal-metal bond: Cr2(oxindolate)4(oxindole)2

The title compound has been prepared by reaction of (C₅H₅)₂Cr with oxindole (indole with CO in place of CH₂ at the 2-position). Red single crystals belong to space group P2₁/c with a = 10.107(4) Å, b = 22.496(7) Å, c = 9.210(3) Å, β = 93.26(3)°, V = 2091(2), and Z = 2. The centrosymmetric molecule has a CrCr distance of 2.495(4) Å. The mean CrO and CrN distances for the bonds to bridging oxindolate anions are 2.024(7) and 2.065(8) Å, respectively. There is an oxindole molecule bound at each end with a CrO axial bond of length 2.341(8) Å and a hydrogen bond from the oxindole NH group to an equatorial oxygen atom of length 2.83(1) Å. The significance of this compound with respect to CrCr bonding is discussed.     

Cluster condensation reactions. The synthesis and crystal and molecular structure of Os6(CO)14(μ2-PPh2)2(μ3-S)3(μ4-S)

Thermal degradation of the cluster compound Os₃(CO)₈(PPh₂H)(μ₃-S)₂ (I) at 125°C leads to decarbonylation and formation of the new ligand bridged hexanuclear cluster Os₆(CO)₁₄(μ-PPh₂)₂(μ₃-S)₃(μ₄-S) (II) in 11% yield. Space Group: P$\text{1}$, No. 2, a 10.427(5), b 13.552(3), c 17.919(3) Å, α 84.87(2), β 75.41(3), γ 78.43(3)°, V 2399(2) ųZ = 2, _?calc 2.82 g cm^?3. The structure was solved by the heavy atom method and refined (3223 reflections) to the final residuals R = 0.042 and R_w = 0.036. The molecule consists of two sulfido bridged open triosmium clusters which are linked by a bridging sulfido ligand and a bridging diphenylphosphino ligand.     

The reaction of Ru3(CO)12 and Os3(CO)12 with PH2Ph; the x-ray crystal structures of HRu3(CO)10(PHPh) and H2Ru3(CO)9(PPh)

Twelve new trinuclear complexes containing terminal PH₂Ph, edge-bridging PHPh and/or capping PPh ligands have been isolated from the reaction of M₃(CO)₁₂ (M = Ru or Os) with PH₂Ph in refluxing solvents. HRu₃(CO)₁₀(PHPh) (IIIa) crystallises in the monoclinic space group P2₁/c with a = 8.761(3), b = 11.402(4), c = 22.041(7) Å,β = 98.89(2)°, and Z = 4. The structure was solved by a combination of direct methods and Fourier difference techniques, and refined by blocked-cascade least squares to R = 0.027 for 3676 unique observed intensities. The X-ray analysis shows that one edge of the Ru₃ triangle is bridged by a hydride and the PHPh ligand, and that the phosphorus-bound hydrogen atom lies over the metal triangle and the phenyl group away from it. This provides an explanation for the ready formation of the capped species H₂Ru₃(CO)₉(PPh) (Va) on pyrolysis of the edge-bridged complex as opposed to the previously reported conversion of HOs₃(CO)₁₀(NHPh) to an orthometallated derivative under similar conditions. An X-ray analysis of H₂Ru₃(CO)₉-(PPh) (Va) confirms the capped geometry. the complex crystallises in the monoclinic space group P2₁/n with a = 9.323(4), b = 15.110(6), c = 45.267(15) Å,β = 91.84(3)°, and Z = 12. the structure was solved and refined using the same techniques as described previously. The final residual R is 0.061 for 4839 reflections. Some reactions of Va show that the phosphorous cap is difficult to displace and stabilises the molecule with respect to decomposition to non-cluster species.     

Structural studies of complexes containing the coordinated methyldisulphido ligand: The crystal structure of [Os (η2-S2CH3) (CO)2 (P (C6H5)3)2] ClO4·12 C6H6.

Crystal and molecular structures of the title compound have been determined from a three-dimentional X-ray analysis usinq diffractometer data. The crystals are triclinic, space group P$\text{1}$, with Z = 2 in a unit cell of dimensions a = 14.23(1), b = 17.30(1), c = 10.44(1) Å, α = 102.1(2), β = 102.7(2), γ = 105.5(2)°. Full matrix least squares refinement has given a final R-factor of 0.060 for 4628 reflections for which I > 3σ(I).The crystal structure consist of discrete cations and anions, together with benzene molecules of crystallisation which are situated about the crystallographic centres of symmetry and serve a purely space-filling role. In the cation coordination about the osmium atom is that of a distorted octahedron, comprising the two triphenylphosphine groups (mutually trans), the two carbonyl groups (mutually cis) and the dihapto S₂Me group. The Os-P distances of 2.420 and 2.419(3) Å are normal. The S₂Me group is nearly symmetrically coordinated with Os-S(l) 2.426(4)Å and Os-S(3) 2.442(4) Å. Other bonds and angles in this ligand are S(1)-S(2) 2.022(7) Å, S(1)-CH₂ 1.81(2) Å, and S(2)-S(1)-CH₃ 105.4(6)°. The observed geometry is similar to that in [Ir(S₂) (Ph₂PCH₂CH₂PPh₂)₂Cl.Ch₃CN.     

The crystal and molecular structure of Rh2(CH3CO2)4[HCON(CH3)]2—effect of ligands on metalmetal bonding

The structure of Rh₂(CH₃CO₂)₄(DMF)₂ {DMF = HCON(CH₃)₂} has been determined by single crystal X-ray methods. The compound crystallizes with eight formula units in a cell of dimensions: a = 29.438(7) Å, b = 7.978(2) Å, c = 20.279(5) Å, β = 113.20(4)°, V = 4377.5 ų, space group C2/c. The structure has been refined by full-matrix least-squares method to a final R = 0.030 for the 4156 observed data. Two Rh(II) atoms are linked by four acetate groups forming a dimeric unit, where the RhRh distance is 2.383(1) Å. The coordination sphere about each Rh atom is completed by a DMF molecule; the average RhO(DMF) distance is 2.296(3) Å.     

Structure cristalline de Cu4(PO4)2O

Cu₄(PO₄)₂O is a new copper-rich phosphate. The preparation is described. The unit cell is triclinic, $\text{P}\text{1}$, with a = 7.528 Å, b = 8.090 Å, c = 6.272 Å; α = 113.68°, β = 81.56°, γ = 105.77°. The structure was solved from 1526 independent reflections using Patterson and Fourier syntheses. The final R value is 0.041 for the 1217 strongest reflections. Copper sites form a three-dimensional framework. The structure consists of homogeneous layers of copper and oxygen atoms parallel to the (012) plane. Phosphorus atoms are inserted between copper and oxygen layers.     

The crystal structure of Cu4(PO4)2O

Cu₄(PO₄)₂O crystallizes in the space group $\text{P}\text{1}$ with a = 7.5393(8) Å, b = 8.1021(9) Å, c = 6.2764(8) Å, α = 113.65(1)°, β = 98.42(1)° and γ = 74.19(1)°. The structure was refined by full-matrix least-squares techniques using automatic diffractometer data to R = 0.046 (R_w = 0.056). Four unique copper atoms are in six, five-, and four-coordinated polyhedra which are linked together to form a three-dimensional network. The structure is best described in terms of a cubic close-packed array of oxygen atoms with one-tenth of the possible anion sites vacant.     

Kristall- und molekülstruktur vonzwei metallcarbonyl-derivaten des PH3: (CO)3Cr(PH3)3 und (CO)5Cr(PH3)

The structures of two carbonylphosphine complexes of chromium were determined by X-ray analysis. cis-Tricarbonyltriphosphinechromium(0), [(CO)₃(PH₃)₃Cr], crystallizes in space group P2₁/m with a = 6.90± 0.01, b = 11.29±0.02, c = 6.41±0.01 Å, β = 93.80±0.08°, Z=2. The structure was solved by conventional methods and refined by least squares (R₁ = 0.056). The idealized octahedral molecule shows approximate C_3v, symmetry. The mean CrP-distance is 2.346±40.003 Å. Pentacarbonylphosphinechromium, [(CO)₅(PH₃)Cr], crystallizes in spacegroup Pnma with a = 12.23±0.02, b = 11.33±0.02, c = 6.61 ±0.01 Å, Z = 4. Cell dimensions and structural parameters are very similar to those of hexacarbonylchromium(0). In the crystal the PH₃ group is disordered over three mutually cis-positions of the coordination octahedron.     

Platinum derivatives of decafluorophosphorobenzene and decafluoroarsenobenzene. The crystal structure of Pt(PPh3)2 (PC6F5)2

The platinum complexes Pt(PPh₃)₂ (PC₆F₅)₂ and Pt(PPh₃)₂(AsC₆F₅)₂ have been isolated from reactions of Pt(PPh₃)₃ with (PC₆F₅)₄ and (AsC₆F₅)₄ respectively. A single-crystal X-ray analysis of Pt(PPh₃)₂(PC₆F₅)₂ has shown that the compound crystallizes in space group P2₁ with a = 9.286(5), b = 20.95(1), c = 11.226(5) Å, β = 90.7(1)°, Z = 2. The structure has been solved by Patterson and Fourier methods and refined to R = 0.043 from three-dimensional diffractometer data. The complex contains the decafluorophosphorobenzene unit C₆F₅PPC₆F₅ bound through each P atom to the platinum. Coordination around the platinum is distorted square planar; the dihedral angle between the two PtP₂ planes is 20.4°.     

Substitution in barium-fluoride apatite: The crystal structures of Ba10(PO4)6F2, Ba6La2Na2(PO4)6F2 and Ba4Nd3Na3(PO4)6F2

The crystal structures of the apatites Ba₁₀(PO₄)₆F₂(I), Ba₆La₂Na₂(PO₄)₆F₂(II) and Ba₄Nd₃Na₃(PO₄)₆F₂ (III) have been determined by single-crystal X-ray diffraction. All three compounds crystallize in a hexagonal apatite-like structure. The unit cells and space groups are: I, a = 10.153(2), c = 7.733(1)Å, $\text{P6}{}_3\text{m}\text{; a = 9.9392(4), c = 7.4419(5)}$Å, $\text{P}\text{6}$; III, a = 9.786(2), c = 7.281(1)Å, $\text{P}\text{3}$. The structures were refined by normal full-matrix crystallographic least squares techniques. The final values of the refinement indicators R_w and R are: I, R_w = 0.026, R = 0.027, 613 observed reflections; II, R_w = 0.081, R = 0.074, 579 observed reflections; III, R_w = 0.062, R = 0.044, 1262 observed reflections.In I, the Ba(1) atoms located in columns on threefold axes, are coordinated to nine oxygen atoms; the Ba(2) sites form triangles about the F site and are coordinated to six oxygen atoms and one fluoride ion. The fluoride ions are statistically displaced ～0.25 Å from the Ba(2) triangles. This displacement of the F ions is analogous to the displacement of OH ion in Ca₁₀(PO₄)₆(OH)₂.The structures of II and III contain disordered cations. In II there is disorder between La and Na in the column cation sites as well as triangle sites. In III, Nd and Na ions are ordered in the column sites, but there is disorder among Ba and the remaining Nd and Na ions in the triangle sites to give an average site population of $\text{2}\text{3}\text{Ba}\text{,}\text{1}\text{6}\text{Nd}\text{,}\text{1}\text{6}\text{Na}$. The coordination of the rare earth ions and Na ions in the ordered column sites are nine and six oxygens, respectively, in accord with the greater charge of the rare earth ions as compared with Na. The F ions in both II and III suffer from considerable disorder in position, and their locations are not precisely known.     

Idle spin behavior of the shifted hexagonal tungsten bronze type compounds FeIIFeIII2F8(H2O)2 and MnFe2F8(H2O)2

Fe^IIFe^III₂F₈(H₂O)₂ and MnFe₂F₈(H₂O)₂, grown by hydrothermal synthesis ($\text{P ? 200}\text{MPa}\text{, T = 450}\text{or}\text{380°}\text{C}$), crystallize in the monoclinic system with cell dimensions (Å): a = 7.609(5), b = 7.514(6), c = 7.453(4), β = 118.21(3)°; and a = 7.589(6), b = 7.503(8), c = 7.449(5), β = 118.06(3)°, and space group $\text{C2}\text{m}\text{, Z = 2}$. The structure is related to that of $\text{WO}{}_3\text{·}\text{1}\text{3}\text{H}{}_2\text{O}$. It is described in terms of perovskite type layers of Fe³⁺ octahedra separated by Fe²⁺ or Mn²⁺ octahedra, or in terms of shifted hexagonal bronze type layers. Both compounds present a weak ferromagnetism below T_N (157 and 156 K, respectively). Mössbauer spectroscopy points to an “idle spin” behavior for Fe^IIFe^III₂F₈(H₂O)₂: only Fe³⁺ spins order at T_N, while the Fe²⁺ spins remain paramagnetic between 157 and 35 K. Below 35 K, the hyperfine magnetic field at the Fe²⁺ nuclei is very weak: H_hf = 47 kOe at T = 4.2 K. For MnFe₂F₈(H₂O)₂, Mn²⁺ spin disorder is expected at 4.2 K. This “idle spin” behavior is due to magnetic frustration.     

Specific heat measurements on the magnetic layer compounds(BA)2Cu(Ox)2 and (CHA)2Cu(Ox)2·H2O

Specific heat data on (BA)₂Cu(Ox)₂ and (CHA)₂Cu(Ox)₂·H₂O below 1 K are reported (BA = C₆H₅ CH₂NH₃⁺, CHA = C₆H₃⁺, Ox = C₂O₄²). The magnetic contributions have the form of broad maxima, occurring near 0.15. A λ-type anomaly is observed for (BA)₂Cu(Ox)₂ at T_c = 0.116(3) K. For (CHA)₂Cu(Ox)₂·H₂O no such ordering is seen.(BA)₂Cu(Ox)₂ appears to be a quadratic S = 1/2 Heisenberg antiferromagnet with J/k = ?0.145 (3) K. The compound (CHA)₂Cu(Ox)₂·H₂O shows a behaviour that is in between 1-D and 2-D S = 1/2 Heisenberg antiferromagnetism.     

Ligand substitution of FeRu2(CO)12 and Fe2Ru(CO)12 with tertiary phosphines and phosphites

Ligand substitution of the mixed-metal clusters FeRu₂(CO)₁₂ and Fe₂Ru(CO)₁₂ with triphenylphosphine and trimethylphosphite has been studied. Mono- and di-substituted derivatives have been synthesized and characterized structurally. The following crystal and molecular structures are reported: Fe₂Ru(CO)₁₁PPh₃: triclinic, space group P$\text{1}$, a 9.203(2), b 11.903(3), c 15.117(4) Å, α 81.54(2), β 87.28(2), γ 66.72(2)°, Z = 2; Fe₂Ru(CO)₁₁P(OMe)₃: orthorhombic, space group Pna2₁, a 17.220(5), b 14.572(4), c 8.708(6) Å, Z = 4, FeRu₂(CO)₁₁PPh₃: monoclinic, space group P2₁/n, a 11.435(3), b 16.034(5), c 16.642(4) Å, β 93.35(2)°, Z = 4; FeRu₂(CO)₁₀(PPh₃)₂: orthorhombic, space group Pccm, a 14.854(4), b 17.180(7), c 16.786(12) Å, Z = 4.Ligand substitution is found to occur preferentially at the ruthenium centers of the FeRu₂ and Fe₂Ru clusters. Monosubstitution causes expansion of both of the clusters while the overall geometry is practically unchanged. Disubstitution of FeRu₂(CO)₁₂ causes contraction of the cluster and leads to a formation of carbonyl bridges. The structural trends have been interpreted in terms of electronic and packing effects of ligand substitution. The X-ray structures of Fe₂Ru(CO)₁₂ and FeRu₂(CO)₁₂ are not known; the ligand substitution studies indicate that Fe₂Ru(CO)₁₂ has the same structure as Fe₃(CO)₁₂, and that FeRu₃(CO)₁₂ does not have a Ru₃(CO)₁₂ structure as postulated previously from the IR studies.     

Synthesis and x-ray crystallographic characterization of (μ3-Bi)2Fe3(CO)9: A reformulation of Hieber's Bi2Fe5(CO)20

When [HFe(CO)₄]^? is treated first with NaBiO₃ and then dilute H₂SO₄, a complex mixture of neutral metal carbonyl clusters results, some of which can be extracted into petroleum ether. Upon prolonged standing the extract yields a precipitate which has been characterized by X-ray crystallography as Bi₂Fe₃(CO)₉.The complex Bi₂Fe₃(CO)₉ crystallizes in the centrosymmetric orthorhombic space group Cmcm (D_2h¹⁷; No. 63) with a 10.616(2) Å, b 13.458(3) Å, c 11.347(3) Å, V 1621.1(7) ų and Z = 4. Single-crystal X-ray diffraction data (Mo-K_α, 2θ = 4.5–55.0°) were collected on a Syntex P2₁ four-circle diffractometer and the structure was refined to R_F 5.4% and R_WF 4.5% for all 1039 independent data (R_F 4.5% and R_WF 4.5% for those 851 reflections with |F₀| > 3.0σ(|F₀|)). The molecule lies on a site of crystallographic C_2v symmetry and is disordered. The individual molecules have a trigonal bipyramidal Bi₂Fe₃ core with the bismuth atoms occupying the apical sites (BiFe 2.617(2)–2.643(2) Å, FeFe 2.735(5)–2.757(5) Å). Each iron atom is linked to three terminal carbonyl ligands and the molecule has approximate C_3h symmetry. The nine peripheral oxygen atoms are ordered and define a tricapped trigonal prism. The equatorial iron atoms are disordered with the two Fe₃ triangles mutually displaced by approximately 30°; the disordered ensemble has approximate D_3h symmetry.     

1,2-Hydrogen abstraction: the characterization of [Li(CH3)2N(CH2)2N(CH3)2]2 [C12H8]. A dilithium complex obtained by the 1,2 deprotonation of acenaphthylene

The reaction of n-butyllithium chelated to N,N,N′,N′-tetramethylethylenediamine (TMEDA) with acenaphthene results in 1,2-hydrogen abstraction to give the dilithio complex of acenaphthylene, [Li(CH₃)₂N(CH₂)₂N(CH₃)₂]₂[C₁₂H₈]. This compound was isolated as a crystalline product and characterized by single crystal X-ray crystallography. [Li(CH₃)₂N(CH₂)₂N(CH₃)₂]₂[C₁₂H₈] crystallizes with a unit cell of a = 23.164(10), b = 25.609(10) and c = 8.495(6) Å in the orthorhombice space group Fdd2. The calculated density is 1.04 g cm^?3 for 8 molecules per unit cell. The observed density is 1.03(4) g cm^?3. 1412 unique reflections were measured on a full circle X-ray diffractometer. The light atom, acentric structure was solved by the symbolic addition technique and refined by full matrix least squares to R₁ = 0.058 and R₂ = 0.056.The acenaphthylene fragment is nearly planar. The effect of charge transfer is evidenced in the short C(3)C(4) bond distance of 1.30(3) Å and the lengthening of the C(1)C(2) bond length from the localized olefinic bond distance of 1.34 to 1.42(2) Å. The two LiTMEDA fragments are coordinated to both sides of the five membered carbon atom ring of the acenaphthylene group.     

Synthesis and structure of the heterotrinuclear chromium-palladium clusters (RC5H4CrCl)2-(μ3S)(μ-SCMe3)2Pd(PPh3) with ferromagnetic exchange interactions over the CrSCr system

Reactions of (RC₅H₄)₂Cr₂(SCMe₃)₂S(I, R = H; II, R = Me) with (PPh₃)₂PdCl₂ in benzene at 20°C gives trinuclear complexes (RC₅H₄)₂Cr₂Cl₂(μ₃-S)(μ-SCMe₃)₂Pd(PPh₃)(III, R = H; IV, R = Me). The structure of IV as a monobenzene solvate is established by an X-ray analysis (black-green triclinic crystals space group P$\text{1}$ with a = 11.403(4), b = 14.933(5), c = 14.131(5) Å, α = 99.13(3), β = 112.72(3), γ = 95.65(3)°, V = 2201.6 Å, Z = 2; IV·C₆H₆). The structure was solved by direct methods and refined in an anisotropic approximation to R = 0.046, R_w = 0.058 for 7643 reflections with I ? 2σ(I). In the molecule of IV metal atoms are separated by non-bonding distances (Cr … Cr 4.079(I), Cr … Pd 3.230(I) and 3.380(I) Å) but linked by the bridging tridentate sulphur atom (CrS 2.339(2) and 2.329(2), PdS 2.327(2) Å), and two SCMe₃ groups between Pd and Cr (CrS 2.396(2) and 2.403(2), PdS 2.350(2) and 2.381(2) Å, Cr?Pd 85.14(6) and 89.92(6)°). The Cl atoms are transferred from Pd to Cr atoms (CrCl 2.308(2) Å) and being terminally coordinated are in trans-positions to each other (as well as η-CH₃C₅H₄ rings) with respect to the Cr₂Pd plane. Cr atoms in III and IV exhibit ferromagnetic exchange interactions over the Cr?Cr system (+2J = 28 and 11 cm^?1, respectively).