Thiemo Marx

Stannaborate Transition Metal Chemistry: Ligand Properties, Reactivity, and Density Functional Theory Calculations of Platinum and Palladium Complexes

Three stannaborate complexes of platinum(II) and a novel stannoborate palladium(II) derivative have been prepared in excellent yield. The tin transition metal bond is formed through nucleophilic substitution and the resulting complexes [Bu3MeN] [trans-[(Et3P)2Pt(SnB11H11)H]] (6), [trans-[(Et3P)2Pt(SnB11H11)(CNtBu)]] (7), [Bu3MeN]2[trans-[(Et3P)2Pt(SnB11H11)2-(CNtBu)]] (8), and [Bu3MeN][(dppe)-Pd(SnB11H11)Me] (12) (dppe = 1,2-bis-(diphenylphosphanyl)ethane) were characterized by NMR spectroscopy and elemental analysis. In the cases of the zwitterion 7, the pentacoordinated complex 9, the palladium salt 12 and [(triphos)Pt(SnB11H11)] (10) (triphos = 1,1,1-tris(diphenylphosphanylmethyl)ethane), their solid-state structures are determined by X-ray crystal structure analyses. The trans influence of the [SnB11H11] ligand is evaluated from the results of the IR spectroscopy and X-ray crystallographic structures of complexes 6, 7, and 12. The dipole moment of the zwitterion 7 is calculated by density functional theory (DFT) methods. The alignment of the dipole moments of the polar molecules 7 and 12 in the solid state is discussed.

STANNA-CLOSO-DODECABORATE : A NUCLEOPHILE IN TRANSITION METAL CHEMISTRY

Reactions of the stannaborate salt [NBu4]2[SnB11H11] (1) with the organometallic electrophiles [CpFe(CO)2Br], [(C7H7)Mo(CO)2I], and [CpNi(PPh3)Cl] resulted in substitution of the halide to give the stannaborate coordination products [NBu4][CpFe(CO)2(SnB11H11)] (2), [NBu4][(C7H7)Mo(CO)2(SnB11H11)] (3), and [NBu4][CpNi(PPh3)(SnB11H11)] (4) in high yields. Single crystals of the air- and moisture-stable products have been characterized by X-ray crystal structure analyses.

Coordination of acloso-Cluster at Rhodium and Iridium

Stanna-closo-dodecaborate [Bu3MeN]2[SnB11H11] reacts as a nucleophile with the rhodium and iridium electrophiles of type [Cp*M(bipy′)Cl][BF4] under formation of a transition metal tin bond. The zwitterionic molecules [Cp*M(bipy′)(SnB11H11)] (with M = Rh, Ir) were characterized by NMR spectroscopy, elemental analyses and X-ray crystal structure analyses. A high dipole moment of 25.67 D was calculated by DFT methods in the case of the rhodium derivative. Koordination eines closo-Clusters an Rhodium und Iridium Der Stanna-closo-dodecaboratcluster [Bu3MeN]2[SnB11H11] reagiert mit den Ubergangsmetallelektrophilen [Cp*M(bipy′)Cl][BF4] von Rhodium und Iridium unter Bildung einer Zinn–Metall Bindung. Die zwitterionischen Reaktionsprodukte [Cp*M(bipy′)(SnB11H11)] (mit M = Rh, Ir) wurden durch NMR-Spektroskopie, Elementaranalysen sowie Kristallstrukturbestimmungen charakterisiert. Im Fall der Rhodiumverbindung wurde ein Dipolmoment von 25.67 D durch DFT Methoden berechnet.

Synthesis and structure of [Zr{η5:η1-C9H6B(NiPr2)NPh}2]: a new complex with a boron-bridged amido-indenyl ligand

A boron-bridged amido-cyclopentadienyl ligand was recently shown to form constrained-geometry titanium-complexes that are capable of olefin polymerisation. Here, the synthesis of the corresponding amido-indenyl ligand η 1 -C 9 H 7 B(N i Pr 2 )N(H)Ph (C 9 H 7 =indenyl) ( 2a / 2v ) and its allyl–vinyl isomerisation are discussed. Deprotonated 2a reacts with ZrCl 4 to give the strongly distorted zirconocene-type complex [Zr{η 5 :η 1 -C 9 H 6 B(N i Pr 2 )NPh} 2 ] ( 3 ) in a 2:1 reaction. All compounds have been characterised by multinuclear NMR methods and structures of both the ligand 2a and the complex 3 have been confirmed by X-ray diffraction.

Platinum complexes of stanna-closo-dodecaborate

Abstract The platinum(II)chlorides cis -L 2 PtCl 2 (LPPh 3 , PEt 3 ), (dppe)PtCl 2 , trans (Ph 3 P) 2 Pt(Cl)Ph, (dppe)Pt(Cl)Me and (dppe)Pt(Cl)Ph were treated with [Bu 3 MeN] 2 [SnB 11 H 11 ] ( 1 ) to give the air and moisture inert stannaborate substituted complexes [Bu 3 MeN] 2 [ trans -L 2 Pt(SnB 11 H 11 ) 2 ] ( 2 : LPPh 3 , 3 : LPEt 3 ), [Bu 3 MeN] 2 [(dppe)Pt(SnB 11 H 11 ) 2 ] ( 4 ), [Bu 3 MeN][ trans -(Ph 3 P) 2 Pt(SnB 11 H 11 )Ph] ( 8 ), [Bu 3 MeN][(dppe)Pt(SnB 11 H 11 )Me] ( 9 ) and [Bu 3 MeN][(dppe)Pt(SnB 11 H 11 )Ph] ( 10 ). The nearly square planar coordination at the transition metal centre in the anion of 8 was confirmed by X-ray crystal structure analysis. (dppe)PtCl 2 reacts with one equivalent of 1 to give a 1:1 mixture of 4 and (dppe)PtCl 2 . Reaction of 9 and 10 with one equivalent of HCl resulted not in the isolation of the monochloride [(dppe)Pt(SnB 11 H 11 )Cl] − ( A ), instead the 1:1 mixture between was 4 and (dppe)PtCl 2 isolated. From the reaction of [(triphos)PtCl][BF 4 ] and 1 a zwitterionic platinum complex (triphos)Pt(SnB 11 H 11 ) ( 11 ) was isolated.

A Zwitterionic Platinum Complex with a Carbene Ligand

Abstract A new stannaborate complex of platinum is prepared from the reaction of [Bu3MeN]2[trans- (Et3Pt)2Pt(SnB11H11)2] and 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (dpdmiy). [trans- (Et3P)2Pt(SnB11H11)(dpdmiy)] has been analyzed by X-ray crystallography and NMR spectroscopy.