Koordinativ ungesättigte Dirutheniumkomplexe: Synthese und Kristallstrukturen von [Ru2(CO)n(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] (n = 4; 5) und [Ru2(CO)4(μ‐CH2)(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)]

Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X‐ray Crystal Structures of [Ru₂(CO)_n(μ‐H)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] (n = 4; 5) and [Ru₂(CO)₄(μ‐CH₂)(μ‐H)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] The reaction of [Ru₂(μ‐CO)(CO)₅(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] ( 2 ) with dppm yields the dinuclear species [Ru₂(μ‐CO)(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 3 ) (dppm = Ph₂PCH₂PPh₂). Under thermal or photolytic conditions 3 loses very easily one carbonyl ligand and affords the corresponding electronically and coordinatively unsaturated complex [Ru₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 4 ). 4 is also obtainable by an one‐pot synthesis from [Ru₃(CO)₁₂], an excess of ^tBu₂PH and stoichiometric amounts of dppm via the formation of [Ru₂(CO)₄(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)₂] ( 1 ). 4 exhibits a Ru–Ru double bond which could be confirmed by addition of methylene to the dimetallacyclopropane [Ru₂(CO)₄(μ‐CH₂)(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 5 ). The molecular structures of 3 , 4 and 5 were determined by X‐ray crystal structure analyses.     

Koordinativ ungesättigte Dieisenkomplexe: Synthese und Kristallstrukturen von [Fe2(CO)4(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] und [Fe2(CO)4(μ‐CH2)(μ‐H)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)]

Coordinatively Unsaturated Diiron Complexes: Synthesis and Crystal Structures of [Fe₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] and [Fe₂(CO)₄(μ‐CH₂)(μ‐H)(μ‐P^tBu₂)(μ‐Ph₂PCH₂PPh₂)] [Fe₂(μ‐CO)(CO)₆(μ‐H)(μ‐P^tBu₂)] ( 1 ) reacts spontaneously with dppm (dppm = Ph₂PCH₂PPh₂) to give [Fe₂(μ‐CO)(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 2 c ). By thermolysis or photolysis, 2 c loses very easily one carbonyl ligand and yields the corresponding electronically and coordinatively unsaturated complex [Fe₂(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 3 ). 3 exhibits a Fe–Fe double bond which could be confirmed by the addition of methylene to the corresponding dimetallacyclopropane [Fe₂(CO)₄(μ‐CH₂)(μ‐H)(μ‐P^tBu₂)(μ‐dppm)] ( 4 ). The reaction of 1 with dppe (Ph₂PC₂H₄PPh₂) affords [Fe₂(μ‐CO)(CO)₄(μ‐H)(μ‐P^tBu₂)(μ‐dppe)] ( 5 ). In contrast to the thermolysis of 2 c , yielding 3 , the heating of 5 in toluene leads rapidly to complete decomposition. The reaction of 1 with PPh₃ yields [Fe₂(CO)₆(H)(μ‐P^tBu₂)(PPh₃)] ( 6 a ), while with ^tBu₂PH the compound [Fe₂(μ‐CO)(CO)₅(μ‐H)(μ‐P^tBu₂)(^tBu₂PH)] ( 6 b ) is formed. The thermolysis of 6 b affords [Fe₂(CO)₅(μ‐P^tBu₂)₂] and the degradation products [Fe(CO)₃(^tBu₂PH)₂] and [Fe(CO)₄(^tBu₂PH)]. The molecular structures of 3 , 4 and 6 b were determined by X‐ray crystal structure analyses.     

[2-(N,N-Dimethylaminomethyl)ferrocenyl] as a ligand towards mercury

The diorganomercurial bis[2-(N,N-dimethylaminomethyl)ferrocenyl]mercury(II), (FcN)₂Hg (3), can be obtained by the symmetrisation of the heteroleptic (FcN)HgCl (2) with Na₂S₂O₃ or in the transmetallation reaction of 2 with (FcN)Li. By crystallisation only the crystals of rac-(FcN)₂Hg were obtained. X-ray diffraction analysis revealed linear coordinated mercury atom with two η¹-bonded FcN ligands. Additionally, weak chelate interactions exist between mercury and nitrogen atoms of the ---CH₂NMe₂ side chains. According to the ¹H-NMR findings, these interactions are not preserved in solution. Diorganomercurial 3 appears in solution as a mixture of two diastereomers with rac/meso-(FcN)₂Hg ratio of 1:1. This diastereomeric ratio in solution remains constant within a wide temperature range and in different solvents. The NMR spectroscopic data of the heteroleptic organomercurials [(FcN)HgCl]₂·H₂O (1) and (FcN)HgCl (2) indicate the chelate-free structure of this compounds in solution within the studied temperature interval (−80 to 90 °C).     

Ligandverhalten von P‐funktionellen Organozinnhalogeniden: Nickel(II)‐, Palladium(II)‐ und Platin(II)‐halogenid‐Komplexe mit Me2(Cl)SnCH2CH2PPh2

Ligand Behaviour of P‐functional Organotin Halides: Nickel(II), Palladium(II), and Platinum(II) Complexes with Me₂(Cl)SnCH₂CH₂PPh₂ Me₂(Cl)SnCH₂CH₂PPh₂ ( 1 ) reacts with Ni^II, Pd^II, and Pt^II halides in molar ratio 2 : 1 forming the complexes [MX₂{PPh₂CH₂CH₂Sn(Cl)Me₂}₂] (M = Ni, Pd, Pt; X = Cl, Br) ( 3 – 6 , 9 , 10 ) ( 7 , 8 : M = Ni; Br instead of Cl). The nickel complexes were isolated and characterized both as the planar ( 3 , 5 , 7 ) and the tetrahedral ( 4 , 6 , 8 ) isomer. Crystal structure analyses and NMR data indicate for the planar nickel complexes 3 , 5 , 7 and [MCl₂{PPh₂CH₂CH₂Sn(Cl)Me₂}₂] ( 9 : M = Pd; 10 : M = Pt) the existence of intra and intermolecular M–Hal…Sn bridges. In a ligand : metal molar ratio of 3 : 1 the complexes [M^éCl{PPh₂CH₂CH₂Sn^⊖Cl₂Me₂}{PPh₂CH₂CH₂Sn(Cl)Me₂}₂] ( 11 : M = Pd; 12 : M = Pt) are formed which represent intramolecular ion pairs. By dehalogenation of [PdCl₂{PPh₂CH₂CH₂Sn(Cl)Me₂}₂] ( 9 ) with sodium amalgam and graphite potassium (C₈K), respectively, the palladacycles cis‐[Pd{PPh₂CH₂CH₂SnMe₂}₂] ( 13 ) and trans‐[Pd(Cl)PPh₂CH₂CH₂SnMe₂{PPh₂CH₂CH₂Sn(Cl)Me₂}] ( 14 ) are formed. From the compounds 1 , 3 , 9 , 11 , and 12 the crystal structures are determined. All compounds are characterized by ¹H, ³¹P, and ¹¹⁹Sn NMR spectroscopy.     

[{LiCH(CH2CH2OMen)SO2Ph}4] (OMen = Menthyl): Synthesis and First Structure of a Chiral Solvent Free Lithiated Sulfone with a Direct Li–C Bond

R*OCH₂CH₂CH₂SO₂Ph (R*OH = MenOH, (–)‐menthol, ( 3a ); BorOH, (1S)‐(–)‐borneol, ( 3b )) were found to react with n‐BuLi in n‐pentane/n‐hexane and toluene/n‐hexane under deprotonation yielding LiCH(CH₂CH₂OR*)SO₂Ph (R* = Men, ( 4a ); Bor, ( 4b )) which reacted with n‐Bu₃SnCl forming the requisite tri(n‐butyl)tin compounds n‐Bu₃SnCH(CH₂CH₂OR*)SO₂Ph (R* = Men, ( 5a ); Bor, ( 5b )) as diastereomeric mixtures. The identities of 5a and 5b were unambiguously proved by ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopic measurements. Solutions of 4a afforded crystals of [{LiCH(CH₂CH₂OMen)SO₂Ph}₄] ( 4a′ ) for which the structure was determined by single‐crystal X‐ray crystallography. Complex 4a′ crystallized in a tetrameric structure without any additional solvent molecules. There were found direct Li–C bonds (Li1–C1/Li2–C20 2.231(9)/2.236(9) Å). The tetrahedral donor set of Li is completed by three oxygen atoms. One oxygen atom comes from the OMen substituent via intramolecular coordination and two oxygen atoms come from SO₂ groups of neighboured LiCH(CH₂CH₂OMen)SO₂Ph moieties. Thus, a heterocubane structure with a Li₄S₄ core is built up.     

[{Cp*(CO)2Fe}6Sn6O8]2+, ein kationischer Zinnoxocluster mit metallorganischen Substituenten

[{Cp*(CO)₂Fe}₆Sn₆O₈]²⁺, a Cationic Tin Oxo Cluster with Organometallic Substituents The reaction of [{Cp*(CO)₂Fe}SnCl₃] 1 (Cp^* = Pentamethylcyclopentadienyl) with Ag₂O in acetone leads to the formation of [{Cp*(CO)₂Fe}₆Sn₆O₈][AgCl₂]₂( 2 ). 2 contains the novel tin oxo cluster cation [{Cp*(CO)₂Fe}₆Sn₆O₈]²⁺ which consists of six {Cp*(CO)₂Fe}Sn‐groups bridged by eight μ₃ oxygen atoms (Sn—O = 209.2(3)‐212.5(3) pm). The resulting Sn₆O₈ cage exhibits a distorted rhombodocahedral structure. The [AgCl₂]^— anion is essentially linear with a Ag—Cl bond length of 250.3(3) pm.     

Novel Dinuclear Tin(II) and Lead(II) Compounds with 2‐Pyridyl Functionalized Silylamido Ligands

Treatment of R₂SiCl₂ (R = Me, Ph) with 2‐aminopyridine in the presence of NEt₃ led to the formation of the bis(N‐2‐pyridylamino)silanes R₂Si{NH(2‐Py)}₂, which were isolated as pale yellow solids. Crystal structure analyses revealed that both compounds exhibit tetrahedrally coordinated silicon atoms which are linked to two 2‐pyridylamido moieties and two organyl groups (Me or Ph). As a result of intermolecular hydrogen bonding between the NH groups and the pyridyl N atoms the R₂Si{NH(2‐Py)}₂ molecules are catenated in the solid state. Treatment of R₂Si{NH(2‐Py)}₂ with nBuLi afforded the corresponding amides R₂Si{NLi(2‐Py)}₂, which were subsequently reacted with MCl₂ (M = Sn, Pb) to give the dinuclear silylamides [{R₂Si(N‐2‐Py)₂M}₂]. Both the tin and the lead derivatives exhibit closely related molecular structures, in which the tin (or lead) atoms are linked to two amido N atoms and a pyridyl N atom in a distorted trigonal bipyramidal coordination mode.     

Synthesis and Crystal Structures of Aluminum,Gallium and Indium Complexes with Chelating Me2Si(NPh)22– Ligands

The reaction of ECl₃ (E = Al, Ga) with two equivalentsof Li₂Me₂Si(NPh)₂ (in diethyl ether/n‐hexane) leads to the formation of bis‐chelate complexes [Li(OEt₂)₃][E{Me₂Si(NPh)₂}₂] (E = Al ( 1 ), Ga ( 2 )). Compounds 1 and 2 crystallize isotypically in the monoclinic system with a = 1136.42(6), b = 3267.9(1), c = 1360.37(8) pm, β = 94.320(7)° for 1 and a = 1140.88(6), b = 3261.7(2), c = 1360.20(8) pm, β = 94.641(7)° for 2 . Both the compounds display a distorted tetrahedral coordination of the central metal atom to give a spirocyclic EN₄Si₂ core. The Al–N bond lengths are in the range of186.5–186.9 pm and for the Ga–N distances values between 192.3and 193.1 pm are observed. Treatment of InCl₃ with three equivalents of Li₂Me₂Si(NPh)₂ yields the tris‐chelate [{Li(OEt₂)}₃In{Me₂Si(NPh₂)}₃] 3 . Compound 3 crystallizes in the trigonal crystal system , space group R$\bar{3}$ c with a = 1852.4(1), and c = 3300.2(2) pm. The central indium atom is coordinated by threeMe₂Si(NPh)₂^2– ligands in a distorted octahedral arrangement withIn–N bond lengths of 230.8 pm.     

New Transition Metal Clusters with Ligands from Main Groups Five and Six

In both physics and chemistry, increased attention is being paid to metal clusters. One reason for this attitude is furnished by the surprising results that have been obtained from studies of the preparation, structural characterization and physical and chemical properties of the clusters. Whereas investigations of cluster reactivity are at present generally limited to three- or four-membered clusters, successful syntheses of clusters with many more metal atoms have recently been designed. These substances occupy an intermediate position between solid state chemistry and the chemistry of metal complexes. This review presents a versatile method for synthesizing metal clusters: the reaction of complexes of transition metal halides with silylated compounds such as E(SiMe₃)₂ (E = S, Se, Te) and E′R(SiMe₃)₂ (R = Ph, Me, Et; E′ = P, As, Sb). Although some of the compounds thus formed have already been prepared by other routes, the method affords ready access to both small and large transition metal clusters with unusual structures and valence electron concentrations; a variety of reactions in the ligand sphere are also possible.