Highly Strained Heterometallacycles of Group 4 Metallocenes with Bis(diphenylphosphino)methanide Ligands

A study of the coordination chemistry of different bis(diphenylphosphino)methanide ligands [Ph₂PC(X)PPh₂] (X=H, SiMe₃) with Group 4 metallocenes is presented. The paramagnetic complexes [Cp₂Ti{κ²‐P,P‐Ph₂PC(X)PPh₂}] (X=H ( 3 a ), X=SiMe₃ ( 3 b )) have been prepared by the reactions of [(Cp₂TiCl)₂] with [Li{C(X)PPh₂}₂(thf)₃]. Complex 3 b could also be synthesized by reaction of the known titanocene alkyne complex [Cp₂Ti(η²‐Me₃SiC₂SiMe₃)] with Ph₂PC(H)(SiMe₃)PPh₂ ( 2 b ). The heterometallacyclic complex [Cp₂Zr(H){κ²‐P,P‐Ph₂PC(H)PPh₂}] ( 4 aH ) has been prepared by reaction of the Schwartz reagent with [Li{C(H)PPh₂}₂(thf)₃]. Reactions of [Cp₂HfCl₂] with [Li{C(X)PPh₂}₂(thf)₃] gave the highly strained corresponding metallacycles [Cp₂M(Cl){κ²‐P,P‐Ph₂PC(X)PPh₂}] ( 5 aCl and 5 bCl ) in very good yields. Complexes 3 a , 4 aH , and 5 aCl have been characterized by X‐ray crystallography. Complex 3 a has also been characterized by EPR spectroscopy. The structure and bonding of the complexes has been investigated by DFT analysis. Reactions of complexes 4 aH , 5 aCl , and 5 bCl did not give the corresponding more unsaturated heterometallacyclobuta‐2,3‐dienes.     

Four‐Membered Heterometallacyclic d0 and d1 Complexes of Group 4 Metallocenes with Amidato Ligands

A study of the coordination chemistry of different amidato ligands [(R)N?C(Ph)O] (R=Ph, 2,6‐diisopropylphenyl (Dipp)) at Group 4 metallocenes is presented. The heterometallacyclic complexes [Cp₂M(Cl){κ²‐N,O‐(R)N?C(Ph)O}] M=Zr, R=Dipp ( 1 a ), Ph ( 1 b ); M=Hf, R=Ph ( 2 )) were synthesized by reaction of [Cp₂MCl₂] with the corresponding deprotonated amides. Complex 1 a was also prepared by direct deprotonation of the amide with Schwartz reagent [Cp₂Zr(H)Cl]. Salt metathesis reaction of [Cp₂Zr(H)Cl] with deprotonated amide [(Dipp)N?C(Ph)O] gave the zirconocene hydrido complex [Cp₂M(H){κ²‐N,O‐(Dipp)N?C(Ph)O}] ( 3 ). Reaction of 1 a with Mg did not result in the desired Zr(III) complex but in formation of Mg complex [(py)₃Mg(Cl) {κ²‐N,O‐(Dipp)N?C(Ph)O}] ( 4 ; py=pyridine). The paramagnetic complexes [Cp′₂Ti{κ²‐N,O‐(R)N?C(Ph)O}] (Cp′=Cp, R=Ph ( 7 a ); Cp′=Cp, R=Dipp ( 7 b ); Cp′=Cp*, R=Ph ( 8 )) were prepared by the reaction of the known titanocene alkyne complexes [Cp₂′Ti(η²‐Me₃SiC₂SiMe₃)] (Cp′=Cp ( 5 ), Cp′=Cp* ( 6 )) with the corresponding amides. Complexes 1 a , 2 , 3 , 4 , 7 a , 7 b , and 8 were characterized by X‐ray crystallography. The structure and bonding of complexes 7 a and 8 were also characterized by EPR spectroscopy.     

Reaction of Cp2ZrCl2 with Inorganic Amides

The reactions of [η⁵‐Cp₂ZrCl₂] (Cp = η⁵‐C₅H₅) with [K(THF)_n][N(PPh₂)₂] (n = 1.25—1.5) and K[CH(PPh₂NSiMe₃)₂] are reported. The first reaction led to the monoamido complex [η⁵‐Cp₂Zr(Cl)N(PPh₂)₂] in which the {(Ph₂P)₂N}^— ligand — via a phosphorous and the nitrogen atom — is coordinated to the zirconium atom in a chelating (η²) fashion. Reaction of the potassium methanide compound, K{CH(PPh₂NSiMe₃)₂} with zirconocene dichloride yield the carbene‐like mono cyclopentadienyl complex [η⁵‐CpZr(Cl){C(PPh₂NSiMe₃)₂}]. The complex is formed by a salt metathesis and concomitant a cyclopentadiene extrusion.     

Synthesis and Characterization of Multiferrocenyl‐Substituted Group 4 Metallocene Complexes

The reaction of different metallocene fragments [Cp₂M] (Cp=η⁵‐cyclopentadienyl, M=Ti, Zr) with diferrocenylacetylene and 1,4‐diferrocenylbuta‐1,3‐diyne is described. The titanocene complexes form the highly strained three‐ and five‐membered ring systems [Cp₂Ti(η²‐FcC₂Fc)] ( 1 ) and [Cp₂Ti(η⁴‐FcC₄Fc)] ( 2 ) (Fc=[Fe(η⁵‐C₅H₄)(η⁵‐C₅H₅)]) by addition of the appropriate alkyne or diyne to Cp₂Ti. Zirconocene precursors react with diferrocenyl‐ and ferrocenylphenylacetylene under C? C bond coupling to yield the metallacyclopentadienes [Cp₂Zr(C₄Fc₄)] ( 3 ) and [Cp₂Zr(C₄Fc₂Ph₂)] ( 5 ), respectively. The exchange of the zirconocene unit in 3 by hydrogen atoms opens the route to the super‐crowded ferrocenyl‐substituted compound tetraferrocenylbutadiene ( 4 ). On the other hand, the reaction of 1,4‐diferrocenylbuta‐1,3‐diyne with zirconocene complexes afforded a cleavage of the central C? C bond, and thus, dinuclear [{Cp₂Zr(μ‐η¹:η²‐C?CFc)}₂] ( 6 ) that consists of two zirconocene acetylide groups was formed. Most of the complexes were characterized by single‐crystal X‐ray crystallography, showing attractive multinuclear molecules. The redox properties of 3 , 5 , and 6 were studied by cyclic voltammetry. Upon oxidation to 3 ⁿ⁺, 5 ⁿ⁺, and 6 ⁿ⁺ (n=1–3), decomposition occured with in situ formation of new species. The follow‐up products from 3 and 5 possess two or four reversible redox events pointing to butadiene‐based molecules. However, the dinuclear complex 6 afforded ethynylferrocene under the measurement conditions.     

General route for the synthesis of terminal phosphanylphosphido complexes of Zr(IV) and Hf(IV): Structural investigations of the first zirconium complex with a phosphanylphosphido ligand

Reactions of R₂P-P(SiMe₃)Li with [Cp₂MCl₂] (M = Zr, Hf) in hydrocarbons yield the related terminal phosphanylphosphido complexes [Cp₂M(Cl){(Me₃Si)P-PR₂-κP¹}] (R = ⁱPr and ^tBu). The solid state structures of [Cp₂M(Cl){P(SiMe₃)-PⁱPr₂-κP¹}] (M = Zr, Hf) were established by single crystal X-ray diffraction studies. The phosphido-P atoms adopt almost planar geometries and the phosphanyl P atoms adopt pyramidal geometries. The reaction of a mixture of (Me₃Si)₂PLi and Ph₂P-P(SiMe₃)Li with [CpZrCl₃] in toluene yields the dinuclear complex [Cp₂Zr₂Cl₅(Ph₂PPPSiMe₃)(Li THF DME)].     

Highly Strained Heterometallacycles of Group 4 Metallocenes with Bis(diphenylphosphino)amide Ligands

A study regarding coordination chemistry of the bis(diphenylphosphino)amide ligand Ph(2) P-N-PPh(2) at Group?4 metallocenes is presented herein. Coordination of N,N-bis(diphenylphosphino)amine (1) to [(Cp(2) TiCl)(2) ] (Cp=η(5) -cyclopentadienyl) generated [Cp(2) Ti(Cl)P(Ph(2) )N(H)PPh(2) ] (2). The heterometallacyclic complex [Cp(2) Ti(κ(2) -P,P-Ph(2) P-N-PPh(2) )] (3?Ti) can be prepared by reaction of 2 with n-butyllithium as well as from the reaction of the known titanocene-alkyne complex [Cp(2) Ti(η(2) -Me(3) SiC(2) SiMe(3) )] with the amine 1. Reactions of the lithium amide [(thf)(3) Li{N(PPh(2) )(2) }] with [Cp(2) MCl(2) ] (M=Zr, Hf) yielded the corresponding zirconocene and hafnocene complexes [Cp(2) M(Cl){κ(2) -N,P-N(PPh(2) )(2) }] (4?Zr and 4?Hf). Reduction of 4?Zr with magnesium gave the highly strained heterometallacycle [Cp(2) Zr(κ(2) -P,P-Ph(2) P-N-PPh(2) )] (3?Zr). Complexes 2, 3?Ti, 4?Hf, and 3?Zr were characterized by X-ray crystallography. The structures and bondings of all complexes were investigated by DFT calculations.     

Stabilization of the Triphosphallyl Ligand η3‐P3{P(O)H} at Iridium via Alkaline Activation of P4

The selective functionalization of the polyphosphorus moiety Ph₂PCH₂PPh₂PPPP present as a tetrahapto‐ligand in complex [Ir(dppm)(Ph₂PCH₂PPh₂PPPP)]⁺ ( 1 , dppm=Ph₂PCH₂PPh₂) was obtained by reaction of 1 with water under basic conditions at room temperature. The formation of the new triphosphaallyl moiety η³‐P₃{P(O)H} was determined in solution by NMR spectroscopy, and confirmed in the solid state by a single‐crystal X‐ray structure of the stable product [Ir(κ²‐dppm)(κ¹‐dppm)(η³‐P₃{P(O)H})] ( 2 ). In solution, 2 has a fluxional behavior attributable to the four P atoms belonging to the tetraphosphorus moiety in 1 and exhibits a chemical exchange process involving the two PPh₂ moieties of the same bidentate ligand, as determined by 1D and 2D NMR spectroscopy experiments carried out at variable temperature. The mechanism of the reaction was investigated at the DFT level, which suggested a selective attack of an in‐situ generated OH^? anion on one of the non‐coordinated phosphorus atoms of the P₄ moiety. The reaction then evolves through an acid‐assisted tautomerization, which leads to the final compound 2 . Bonding analysis pointed out that the new unsubstituted P₃‐unit in the η³‐P₃{P(O)H} moiety behaves as a triphosphallyl ligand.     

Reactions of Dienes with a Mo(0) Complex with Tetraphosphine Coligand [Mo(P4)(Ph2PCH2CH2PPh2)] (P4 = Meso‐o‐C6H4(PPhCH2CH2PPh2)2)

Reaction of tetraphosphine complex [Mo(κ⁴‐P4)(Ph₂PCH₂CH₂PPh₂)] (1; P4 = meso‐o‐C₆H₄‐(PPhCH₂CH₂PPh₂)₂) with E‐1,3‐pentadiene in toluene at 60 °C gave the η⁴‐diene complex [Mo(η⁴‐E‐1,3‐pentadiene)(κ⁴‐P4)] (2), which is present as a mixture of two isomers due to the orientation of the Me group in the diene ligand. Treatment of 1 with Z‐1,3‐pentadien also resulted in the formation of 2 as the sole product after heating the reaction mixture at 90 °C. Whereas the reaction of 1 with 1,3‐cyclohexadiene at 60 °C afforded the η⁴‐diene complex [Mo(η⁴‐cyclohexadiene)(κ⁴‐P4)] (6), that with cyclopentadiene led to the C‐H bond scission product [η⁵‐C₅H₅)MoH(κ³‐P4)] (7). Detailed structures were determined by X‐ray crystallography for 2, 6,and 7, and fluxional feature of 6 in solution was clarified based on the VT‐NMR studies.     

Variable Bonding Modes of Pyrimidine‐2‐thione in PdII/PtII Complexes [M(η2‐N,S‐pymS)(η1‐S‐pymS)(PPh3)] and [M(η1‐S‐pymS)2(L‐L)] (L‐L = dppm,dppe)

Reactions of pyrimidine‐2‐thione (HpymS) with Pd^II/Pt^IV salts in the presence of triphenyl phosphine and bis(diphenylphosphino)alkanes, Ph₂P‐(CH₂)_m‐PPh₂ (m = 1, 2) have yielded two types of complexes, viz. a) [M(η²‐N, S‐ pymS)(η¹‐S‐ pymS)(PPh₃)] (M = Pd, 1 ; Pt, 2 ), and (b) [M(η¹‐S‐pymS)₂(L‐L)] {L‐L, M = dppm (m = 1) Pd, 3 ; Pt, 4 ; dppe (m = 2), Pd, 5 ; Pt, 6 }. Complexes have been characterized by elemental analysis (C, H, N), NMR spectroscopy (¹H, ¹³C, ³¹P), and single crystal X‐ray crystallography ( 1 , 2 , 4 , and 5 ). Complexes 1 and 2 have terminal η¹‐S and chelating η²‐N, S‐modes of pymS⁻, while other Pd/Pt complexes have only terminal η¹‐S modes. The solution state ³¹P NMR spectral data reveal dynamic equilibrium for the complexes 3 , 5 and 6 , whereas the complexes 1 , 2 and 4 are static in solution state.     

Sulfur‐assisted Chloride and Triphenylphosphine Dissociation of Palladium(II) Complex with Phenyloxythiocarbonyl,PhOC(S), Containing Ligand: X‐Ray Structure of [Pd(PPh3)2{η1‐C(S)OPh}(Cl)]

Treatment of Pd(PPh₃)₄ with phenylchlorothionoformate, PhOC(S)Cl, in dichloromethane at ?20 °C produces the phenyloxythiocarbonyl complex [Pd(PPh₃)₂{η¹‐C(S)OPh}(Cl)], 1 . The ³¹P{¹H} NMR spectrum of 1 shows the dissociation of either the chloride or the triphenylphosphine ligand to form complex [Pd(PPh₃)₂(η²‐SCOPh)][Cl], 2 or the dipalladium complex [Pd(PPh₃)Cl]₂(μ,η²‐SCOPh)₂, 3 . Continuous stirring of the dichloromethane solution of 1 at room temperature for 4 h forms the dipalladinum complex [Pd(PPh₃)Cl]₂(μ,η²‐SCOPh)₂, 3 as the final product. Respective reactions of 1 and Et₂NCS₂Na or dppa {bis(diphenylphosphino)amine} gives complex [Pd(PPh₃){η¹‐C(S)OPh}(η²‐S₂CNEt₂)], 4 or [Pd(PPh₃){η¹‐C(S)OPh}(η²‐dppa)][Cl], 5 . Complex 1 is determined by single‐crystal X‐ray diffraction and crystallized in the monoclinic space group P2₁ with Z = 4. The cell dimensions of 1 are as follows: a = 9.5613(1) Å, b = 33.6732(3) Å, c = 12.2979(1) Å.     

Reactions of Group 4 Metallocene Complexes with Mono‐ and Diphenylacetonitrile: Formation of Unusual Four‐ and Six‐Membered Metallacycles

Reactions of Group 4 metallocene alkyne complexes [Cp′₂M(η²‐Me₃SiC₂SiMe₃)] ( 1 : M=Zr, Cp′=Cp*=η⁵‐pentamethylcyclopentadienyl; 2 a : M=Ti, Cp′=Cp*, and 2 b : M=Ti, Cp′₂=rac‐(ebthi)=rac‐1,2‐ethylene‐1,1′‐bis(η⁵‐tetrahydroindenyl)) with diphenylacetonitrile (Ph₂CHCN) and of the seven‐membered zirconacyclocumulene 3 with phenylacetonitrile (PhCH₂CN) were investigated. Different compounds were obtained depending on the metal, the cyclopentadienyl ligand and the reaction temperature. In the first step, Ph₂CHCN coordinated to 1 to form [Cp*₂Zr(η²‐Me₃SiC₂SiMe₃)(NCCHPh₂)] ( 4 ). Higher temperatures led to elimination of the alkyne, coordination of a second Ph₂CHCN and transformation of the nitriles to a keteniminate and an imine ligand in [Cp*₂Zr(NC₂Ph₂)(NCHCHPh₂)] ( 5 ). The conversion of 4 to 5 was monitored by using ¹H NMR spectroscopy. The analogue titanocene complex 2 a eliminated the alkyne first, which led directly to [Cp*₂Ti(NC₂Ph₂)₂] ( 6 ) with two keteniminate ligands. In contrast, the reaction of 2 b with diphenylacetonitrile involved a formal coupling of the nitriles to obtain the unusual four‐membered titanacycle 7 . An unexpected six‐membered fused zirconaheterocycle ( 8 ) resulted from the reaction of 3 with PhCH₂CN. The molecular structures of complexes 4 , 5 , 6 , 7 and 8 were determined by X‐ray crystallography.     

The Binary Group 4 Azides [PPh4]2[Zr(N3)6] and [PPh4]2[Hf(N3)6]

The binary zirconium and hafnium polyazides [PPh₄]₂[M(N₃)₆] (M=Zr, Hf) were obtained in near quantitative yields from the corresponding metal fluorides MF₄ by fluoride–azide exchange reactions with Me₃SiN₃ in the presence of two equivalents of [PPh₄][N₃]. The novel polyazido compounds were characterized by their vibrational spectra and their X‐ray crystal structures. Both anion structures provide experimental evidence for near‐linear M‐N‐N coordination of metal azides. The species [M(N₃)₄], [M(N₃)₅]^? and [M(N₃)₆]^2? (M=Ti, Zr, Hf) were studied by quantum chemical calculations at the electronic structure density functional theory and MP2 levels.     

Hexanuclear Gold(I) Phosphide Complexes as Platforms for Multiple Redox‐Active Ferrocenyl Units

The synthesis, X‐ray crystal structures, electrochemical, and spectroscopic studies of a series of hexanuclear gold(I) μ₃‐ferrocenylmethylphosphido complexes stabilized by bridging phosphine ligands, [Au₆(P?P)_n(Fc‐CH₂‐P)₂][PF₆]₂ (n=3, P?P=dppm (bis(diphenylphosphino)methane) ( 1 ), dppe (1,2‐bis(diphenylphosphino)ethane) ( 2 ), dppp (1,3‐bis(diphenylphosphino)propane) ( 3 ), Ph₂PN(C₃H₇)‐PPh₂ ( 4 ), Ph₂PN(Ph‐CH₃‐p)PPh₂ ( 5 ), dppf (1,1′‐bis(diphenylphosphino)ferrocene) ( 6 ); n=2, P?P=dpepp (bis(2‐diphenylphosphinoethyl)phenylphosphine) ( 7 )), as platforms for multiple redox‐active ferrocenyl units, are reported. The investigation of the structural changes of the clusters has been probed by introducing different bridging phosphine ligands. This class of gold(I) μ₃‐ferrocenylmethylphosphido complexes has been found to exhibit one reversible oxidation couple, suggestive of the absence of electronic communication between the ferrocene units through the Au₆P₂ cluster core, providing an understanding of the electronic properties of the hexanuclear Au^I cluster linkage. The present complexes also serve as an ideal system for the design of multi‐electron reservoir and molecular battery systems.     

Zum Einfluß der PR3‐Liganden auf Bildung und Eigenschaften der Phosphinophosphiniden‐Komplexe [{η2‐tBu2P–P}Pt(PR3)2] und [{η2‐tBu2P1–P2}Pt(P3R3)(P4R′3)]

Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes XXI The Influence of the PR₃ Ligands on Formation and Properties of the Phosphinophosphinidene Complexes [{η²‐^tBu₂P–P}Pt(PR₃)₂] and [{η²‐^tBu₂P¹–P²}Pt(P³R₃)(P⁴R′₃)] (R₃P)₂PtCl₂ and C₂H₄ yield the compounds [{η²‐C₂H₄}Pt(PR₃)₂] (PR₃ = PMe₃, PEt₃, PPhEt₂, PPh₂Et, PPh₂Me, PPh₂ⁱPr, PPh₂^tBu and P(p‐Tol)₃); which react with ^tBu₂P–P=PMe^tBu₂ to give the phosphinophosphinidene complexes [{η²‐^tBu₂P–P}Pt(PMe₃)₂], [{η²‐^tBu₂P–P}Pt(PEt₃)₂], [{η²‐^tBu₂P–P}Pt(PPhEt₂)₂], [{η²‐^tBu₂P–P}Pt(PPh₂Et)₂], [{η²‐^tBu₂P–P}Pt(PPh₂Me)₂], [{η²‐^tBu₂P–P}Pt(PPh₂ⁱPr], [{η²‐^tBu₂P–P}Pt(PPh₂^tBu)₂] and [{η²‐^tBu₂P–P}Pt(P(p‐Tol)₃)₂]. [{η²‐^tBu₂P–P}Pt(PPh₃)₂] reacts with PMe₃ and PEt₃ as well as with ^tBu₂PMe, PⁱPr₃ and P(c‐Hex)₃ by substituting one PPh₃ ligand to give [{η²‐^tBu₂P¹–P²}Pt(P³Me₃)(P⁴Ph₃)], [{η²‐^tBu₂P¹–P²}Pt(P³Ph₃)(P⁴Me₃)], [{η²‐^tBu₂P¹–P²}Pt(P³Et₃)(P⁴Ph₃)], [{η²‐^tBu₂P¹–P²}Pt(P³Me^tBu₂)(P⁴Ph₃)], [{η²‐^tBu₂P¹–P²}Pt(P³ⁱPr₃)(P⁴Ph₃)] and [{η²‐^tBu₂P¹–P²}Pt(P³(c‐Hex)₃)(P⁴Ph₃)]. With ^tBu₂PMe, [{η²‐^tBu₂P–P}Pt(P(p‐Tol)₃)₂] forms [{η²‐^tBu₂P¹–P²}Pt(P³Me^tBu₂)(P⁴(p‐Tol)₃)]. The NMR data of the compounds are given and discussed with respect to the influence of the PR₃ ligands.     

Synthesis,Reactivity, and Crystal Structure of the η2‐Thiocarbamoyl Palladium Complex [Pd(PPh3)2(η2‐SCNMe2)][PF6]

The η¹‐thiocarbamoyl palladium complexes [Pd(PPh₃)(η¹‐SCNMe₂)(η²‐S₂R)] (R = P(OEt)₂, 2 ; CNEt₂, 3 ) and trans‐[Pd(PPh₃)₂(η¹‐SCNMe₂)(η¹‐Spy)], 4 , (pyS: pyridine‐2‐thionate) are prepared by reacting the η²‐thiocarbamoyl palladium complex [Pd(PPh₃)₂(η²‐SCNMe₂)][PF₆], 1 with (EtO)₂PS₂NH₄, Et₂NCS₂Na, and pySK in methanol at room temperature, respectively. Treatment of 1 with dppm (dppm: bis(diphenylphosphino)methane) in dichloromethane at room temperature gives complex [Pd(PPh₃)(η¹‐SCNMe₂)(η²‐dppm)] [PF₆], 5 . All of the complexes are identified by spectroscopic methods and complex 1 is determined by single‐crystal X‐ray diffraction.     

Synthese,Struktur und Reaktivität von η1und η3‐Allyl‐Rhenium‐Carbonylen

Synthesis, Structure, and Reactivity of η¹‐ and η³‐Allyl Rhenium Carbonyls In (η³‐C₃H₅)Re(CO)₄ one CO ligand can be substituted by PPh₃, pyridine, isocyanide and benzonitrile. With 1,2‐bis(diphenylphosphino)ethylene, 1,1′‐bis(diphenylphosphino)ferrocene and 1,2‐bis(4‐pyridyl)ethane dinuclear ligand bridged complexes are obtained. The η³‐η¹ conversion of the allyl ligand occurs on reaction of (η³‐C₃H₅)Re(CO)₄ with the bidendate ligands 1,2‐bis(diphenylphosphino)ethane and 1,3‐bis(diphenylphosphino)propane and with 2,2′‐bipyridine (L–L) which gives the complexes (η¹‐C₃H₅)Re(CO)₃(L–L). By reaction of (η³‐C₃H₅)Re(CO)₄ with bis(diphenylphosphino)methane the allyl group is protonated and under elemination of propene the complex (OC)₃Re(Ph₂PCHPPh₂)(η¹‐Ph₂PCH₂PPh₂) ( 19 ) with a diphosphinomethanide ligand is formed. On heating solutions of (η³‐C₃H₅)Re(CO)₄ and (η³‐C₃H₅)Re(CO)₃(CN‐2,5‐Me₂C₆H₃) ( 5 ) in methanol the methoxy bridged compounds Re₄(CO)₁₂(OH)(OMe)₃ and Re₂(CO)₄(CN‐2,5‐Me₂C₆H₃)₄(μ‐OMe)₂ ( 20 ) were isolated. The crystal structures of (η³‐C₃H₅)Re(CO)₃(CNCH₂SiMe₃) ( 4 ), [(η³‐C₃H₅)(OC)₃Re]₂‐ (μ‐bis‐(diphenylphosphino)ferrocene) ( 8 ), (η¹‐C₃H₅)Re(CO)₃‐ (bpy) ( 14 ), of 19 , 20 and of (OC)₃Re‐[Ph₂P(CH₂)₃PPh₂]Cl ( 16 ) were determined by X‐ray diffraction.     

1, 9‐Dihydro‐purine‐6‐thione Derivatives of the d8–d10 Metal Ions (PdII,PtII, and CuI): Synthesis,Spectroscopy, and Structures

Reaction of 1, 9‐dihydro‐purine‐6‐thione (puSH₂) in presence of aqueous sodium hydroxide with PdCl₂(PPh₃)₂ suspended in ethanol formed [Pd(κ²‐N⁷,S‐puS)(PPh₃)₂] ( 1 ). Similarly, complexes [Pd(κ²‐N⁷,S‐puS)(κ²‐P, P‐L‐L)] ( 2 – 4 ) {L‐L = dppm (m = 1) ( 2 ), dppp (m = 3) ( 3 ), dppb (m = 4) ( 4 )} were prepared using precursors the [PdCl₂(L‐L)] {L‐L = Ph₂P–(CH₂)_m–PPh₂}. Reaction of puSH₂ suspended in benzene with platinic acid, H₂PtCl₆, in ethanol in the presence of triethylamine followed by the addition of PPh₃ yielded the complex [Pt(κ²‐N⁷,S‐puS)(PPh₃)₂] ( 5 ). Complexes [Pt(κ²‐N⁷,S‐puS)(κ²‐P, P‐L‐L)] ( 6 – 8 ) {L‐L = dppm ( 6 ), dppp ( 7 ), dppb ( 8 )} were prepared similarly. The 1, 9‐dihydro‐purine‐6‐thione acts as N⁷,S‐chelating dianion in compounds 1 – 8 . The reaction of copper(I) chloride [or copper(I) bromide] in acetonitrile with puSH₂ and the addition of PPh₃ in methanol yielded the same product, [Cu(κ²‐N⁷,S‐puSH)(PPh₃)₂] ( 9 ), in which the halogen atoms are removed by uninegative N, S‐chelating puSH^– anion. However, copper(I) iodide did not lose iodide and formed the tetrahedral complex, [CuI(κ¹‐S‐puSH₂)(PPh₃)₂] ( 10 ), in which the thio ligand is neutral. These complexes were characterized with the help of elemental analysis, NMR spectroscopy (¹H, ³¹P), and single‐crystal X‐ray crystallography ( 3 , 7 , 8 , 9 , and 10 ).     

Arene ruthenium metallacycles containing chelating thioamide ligands

Cationic, chiral arene ruthenium complexes of the type [Ru(η⁶-cym)(PPh₃){κ²N,S-PhNC(S)R}]BPh₄ were prepared in high yields by refluxing a mixture containing [(η⁶-cym)RuCl₂]₂, Ph₃P, PhNHC(S)R, NaBPh₄ and Et₃N in MeOH. A series of seven complexes with different thioamide ligands was prepared and fully characterised by spectroscopic methods including NMR spectroscopy and electrospray mass spectrometry. The solid-state structures of two complexes were determined by single crystal X-ray diffraction.     

Preparation and Characterization of a Novel Palladium Complex: cis‐Dichloride(1,2‐bis(diphenylphosphino)vinyl‐P,P′,C)palladium(II)‐(bis(diphenylphosphino)methane‐P,P′)cobaltacarbonyl

A novel palladium complex 4, cis‐dichloride(1,2‐bis(diphenylphosphino)vinyl‐P,P′,C)palladium(II)‐(bis(diphenylphosphino)methane‐P,P′)cobaltacarbonyl, was obtained and characterized from the treatment of [(μ‐Ph₂PCH₂PPh₂)Co₂(CO)₄][(Ph₂PC≡CPPh₂)‐PdCl₂] 3 with hydrochloric acid. The framework of 4 can be regarded as a grouping of two metal‐containing fragments: ‐Co(CO)₂(dppm) and PdCl2(μ‐P,P‐Ph₂PCH=C(‐)PPh₂).     

Hydridoorganostannylene Coordination: Group 4 Metallocene Dichloride Reduction in Reaction with Organodihydridostannate Anions

Organodihydridoelement anions of germanium and tin were reacted with metallocene dichlorides of Group 4 metals Ti, Zr and Hf. The germate anion [Ar*GeH₂]⁻ reacts with hafnocene dichloride under formation of the substitution product [Cp₂Hf(GeH₂Ar*)₂]. Reaction of the organodihydridostannate with metallocene dichlorides affords the reduction products [Cp₂M(SnHAr*)₂] (M=Ti, Zr, Hf). Abstraction of a hydride substituent from the titanium bis(hydridoorganostannylene) complex results in formation of cation [Cp₂M(SnAr*)(SnHAr*)]⁺ exhibiting a short Ti–Sn interaction. (Ar*=2,6-Trip₂C₆H₃, Trip=2,4,6-triisopropylphenyl).