Investigating a Redox Active Samarium Complex in Catalytic Reactions

Herein the synthesis of a new ethynyl ferrocenyl amidinate ligand [Fc−C≡C-{C(Ndipp)$_{2}$H}] (Fc=ferrocenyl; dipp=diisopropylphenyl) and the subsequent formation of the corresponding samarium amido complex [Sm{Fc−C≡C-[C(Ndipp)$_{2}$$_{2}$]}$_{2}${N(SiMe$_{3}$3)$_{2}$}] is reported. [Fc−C≡C-{C(Ndipp)2H}] and [Sm{Fc−C≡C-[C(Ndipp)$_{2}$]}$_{2}${N(SiMe$_{3}$)$_{2}$}] were fully characterized including the study of the complex’ redox properties by cyclovoltammetry. Furthermore, we investigated the catalytic properties of the samarium complex in the intramolecular hydroamination reaction and intermolecular dehydrocoupling of pinacol borane with various amines

Group 14 metallole dianions as η5^5-coordinating ligands

As heavier aromatic analogs of the cyclopentadienides, group 14 dianionic metalloles exhibit more versatile reactivity and coordination modes due to the additional lone pair at the heteroatom. Compared to the well-established chemistry of monoanionic cyclopentadienide ligands, the coordination chemistry with those dianionic ligands remains underexplored. This perspective provides an overview of literature-known examples of group 14 metallole dianions (silole, germole, stannole and plumbole) adopting η$^5$-coordinating modes. The diverse coordination modes and reactivity exhibited by these compounds highlight their potential as intriguing ligands in organometallic chemistry

Forging a Cage into a Chain: Stepwise Transformation of P4_4 by Silylenes to a Si3_3P4_4 Motif

We have discovered a route to access the longest low-valent molecular silaphospha-chain, a seven-membered chain structure that incorporates three silicon and four phosphorus atoms by stepwise activation of white phosphorus (P$_4$) using two different silylene precursors. The chain species was formed via a highly reactive polyphosphide intermediate. The isolation of a stable analogue of this reaction intermediate was achieved by stepwise reaction with mono and bis(silylenes). Due to the rigidity of the ferrocenediyl framework of the bis(silylene), the isomerization process of the chain structure was hampered. Theoretical studies such as natural bond orbital and atoms in molecules analyses of the seven-membered chain species indicated some degree of delocalization of the double bond system

A square planar silylene nickel four-membered ring

Herein the new nickel silylene [PhC(NtBu)2SiNi(C5Me5)]2, which features a square planar central ring motif consisting of two silicon and two nickel atoms is presented. The title compound was obtained by an insertion of the Ni(0) precursor [Ni(cod)2] (cod = 1,5-cyclooctadiene) in the Si–C bond of the silylene [PhC(NtBu)2Si(C5Me5)]. Analytic characterisation including mass spectrometry as well as IR and Raman spectroscopies was combined with quantum chemical calculations to get an insight on the bonding situation within the four-membered Si–Ni-ring

Reactivity of mono- And divalent aluminium compounds towards group 15 nanoparticles

Herein, we present a novel approach towards organometallic group 13/15-compounds, i.e. the reaction of nanoparticular arsenic and antimony with low-valent aluminium species. The reaction of the two-electron reducing agent [AlCp*]$_{4}$ (Cp* = C$_{5}$Me$_{5}$) with arsenic nanoparticles gave rise to a mixture of two unprecedented deca- and dodecanuclear Al–As clusters. In contrast, the analogous transformation with nanoparticular antimony yielded the already known Al–Sb compound [(AlCp*)$_{3}$Sb$_{2}$]. Additionally, two different dialanes [AlCp*X]$_{2}$ (X = Br, I) were employed as one-electron reducing agents, forming calix like coordination compounds upon reaction with nano arsenic. The isolated species significantly enlarge the accessible structural variety of molecular group 13/15 compounds, highlighting the exceptional utility and reactivity of nanoscale group 15 precursors

Substituted bisphosphanylamines as ligands in gold(I) chemistry – synthesis and structures

Dimethyl 5-aminoisophthalate, which is a building block of amino-substituted tetralactam macrocycles, was used as ligand in gold(I) chemistry to form model complexes for macrocyclic gold compounds. Reaction of dimethyl 5-aminoisophthalate with chlorodiphenylphosphine gave the diphosphine compound dimethyl 5-[N,N-bis(diphenylphosphanyl)amino]isophthalate (dmbpaip). This compound can further be reacted with [AuCl(tht)] (tht = tetrahydrothiophene) to give the dinuclear complex [Au(2),Cl(2)(dmbpaip)]. In contrast, treatment of dinbpaip with [Au(tht)(2)]ClO(4) resulted in the ionic compound [Au(2)(dmbpaip)(2)](ClO(4))(2) in which the cation forms an eight-membered Au(2)P(4)N(2) heterocycle. In both gold(I) compounds Au center dot center dot center dot Au interactions are observed. All new compounds were characterized by single-crystal X-ray diffraction

Neutral and cationic enantiopure group 13 iminophosphonamide complexes

Synthesis and reactivity of enantiopure iminophosphonamide ligand L-H (L = [Ph$_{2}$P{N(R)CH(CH$_{3}$)Ph}$_{2}$]) with group 13 metal compounds has been investigated. The reaction of L-H with LiAlH$_{4}$ afforded the aluminium monohydride complex [L$_{2}$AlH]. The monochloride complexes [L$_{2}$MCl] (M = Al, Ga) were accessed by reacting corresponding MCl$_{3}$ (M = Al, Ga) with L-Li. Furthermore, the tetracoordinated aluminium cation [L$_{2}$Al]$^{+}$[GaCl$_{4}$]$^{-}$ and gallium cation [L$_{2}$Ga]$^{+}$[AlCl$_{4}$]$^{-}$ were obtained by chloride abstraction from [L$_{2}$MCl] (M = Al, Ga), respectively. The title complexes represent the first examples of enantiopure group 13 metal complexes coordinated by chiral iminophosphonamides. All complexes have been characterized by single crystal X-ray diffraction, multinuclear NMR, EA and IR studies

From a nanoparticular solid-state material to molecular organo-f-element-polyarsenides

A convenient pathway to new molecular organo-lanthanide-polyarsenides in general and to a f-element complex with the largest polyarsenide ligand in detail is reported. For this purpose, the activation of the solid state material As$^{0}$$_{nano}$ (nanoscale gray arsenic) by the multi electron reducing agents [K(18-crown-6)][(Image Cp\u27\u27$_{2}$ Ln$^{+II}$)$_{2}$(μ-η$^{6}$:η$^{6}$-C$_{6}$H$_{6}$)] (Ln = La, Ce, Cp′′ = 1,3-bis(trimethylsilyl)cyclopentadienyl anion) and [K(18-crown-6)]$_{2}$[(Cp\u27\u27$_{2}$Ln$^{+II}$)$_{2}$(μ-η$^{6}$:η$^{6}$-C$_{6}$H$_{6}$)] (Ln = Ce, Nd) is shown. These non-classical divalent lanthanide compounds were used as three and four electron reducing agents where the product formation can be directed by variation of the applied reactant. The obtained Zintl anions As$_{3}$$^{3-}$, As$_{7}$$^{3-}$, and As$_{14}$$^{4-}$ were previously not accessible in molecular 4f-element chemistry. Additionally, the corresponding compounds with As$_{14}$$^{4-}$-moieties represent the largest organo-lanthanide-polyarsenides known to date