Reactivity of Yellow Arsenic towards Cyclic (Alkyl)(Amino) Carbenes (CAACs)

Different cyclic (alkyl)(amino)carbenes (CAACs) were reacted with yellow arsenic. Several products [(CAAC-n)2(μ,η1:1-As2)] (n=1 (1), 4 (2)), [(CAAC-2)3(μ3,η1:1:1-As4)] (3) and [(CAAC-3)4(μ4,η1:1:1:1- As8)] (6) were isolated due to the differing steric properties of CAAC-1-4. The products contain As2, As4 or As8 units and represent the first examples of CAACs-substituted products of yellow arsenic. The reactivity of As4 was compared with the reactivities of P4 and the interpnictogen compound AsP3, which led to a series of phosphorus-containing derivatives such as ([(CAAC-3)3(μ3,η1:1:1-P4)] (4) and [(CAAC-3)4(μ4,η1:1:1:1-P8)] (7)) and [(CAAC-3)3(μ3,η1:1:1-AsP3)] (5). The products were characterized by spectroscopic and crystallographic methods and DFT computations were performed to clarify their formation pathway

Novel pathways for the coordination and activation of the E4 tetrahedron (E4 = P4, AsP3, As4)

The thesis deals with the activation and coordination of the reactive molecular modifications of phosphorus and arsenic. By carefully chosen reaction conditions, it is possible to selectively break one or more bonds of the native tetrahedral molecules to yield novel structural motifs. Moreover, the highly unstable yellow arsenic can be stabilized in the coordination sphere of transition metal complexes. This stabilized arsenic can be used for further reactivity studies and opens new ways in the chemistry of this fascinating element

The reactivity of the P4-butterfly ligand [{Cp'''Fe(CO)2}2(µ,η1:1-P4)] towards transition metal complexes: Coordination versus rearrangement

The reaction of the P-4 butterfly compound [{Cp'''Fe(CO)(2)}(2)(mu,eta(1:1)-P-4)] (1, Cp''' = (C5H2Bu3)-Bu-t) towards various transition metal complexes is investigated. On the one hand, the reaction of 1 with [(PPh3)Au(tht)][PF6] (tht = tetrahydrothiophene) and [M(CO)(4)(nbd)] (M = Cr, Mo, W; nbd = norbornadiene) yields chelating complexes of the type [{Cp'''Fe(CO)(2)}(2)(mu(3),(1:1:1:1)(eta)-P-4){Au(PPh3)}] (2d) and [{Cp'''Fe(CO)(2)}(2)(mu(3),(1:1:1:1)(eta)-P-4){M(CO)(4)}] (2a-c, M = Cr, Mo, W), respectively, bearing intact P-4 butterfly ligands with exceedingly small bite angles (ca. 65 degrees). The reaction of 1 with Ag[PF6] even afforded the spiro complex [{(Cp'''Fe(CO)(2))(2)(mu(3),(1:1:1:1)(eta)-P-4)}(2)Ag][PF6] (3), in which the silver cation is coordinated in a distorted tetrahedral fashion by two P-4 butterfly motifs. On the other hand, the reaction of 1 with the carbonyl containing Lewis acids Fe-2(CO)(9) or Co-2(CO)(8) leads to rearrangement yielding [{Cp'''Fe(CO)(2)}(2){Co(CO)(3)}(2)(mu(4),(2:2:1:1)(eta)-P-4)] (4), incorporating a folded cyclo-P-4 scaffold, and [{Cp'''Fe (CO)(2)}(2)(mu(4),(1:1:1:3)(eta)-P4CO){Fe(CO)(4)}{Fe(CO)(3)}] (5), displaying a tetraphosphole structural motif obtained after carbonyl insertion, respectively. The products are comprehensively characterized by different spectroscopic methods as well as single crystal X-ray diffraction analysis and theoretical calculations

CCDC 835631: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

Structure and bonding in three-coordinate N-heterocyclic carbene adducts of iron(ii) bis(trimethylsilyl)amide

The molecular structures, chemical bonding and magnetochemistry of the three-coordinate iron(II) NHC complexes [(NHC)Fe{N(SiMe3)2}2] (NHC = IPr, 2; NHC = IMes, 3) are reported

CCDC 835632: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

Synthesis and unprecedented coordination behaviour of a novel 1,2,3-triphosphaferrocene complex

A novel 1,2,3-triphosphaferrocene has been synthesised, which reacts with CuBr to give a 2D polymer, revealing an unprecedented -stacking of the triphospholyl moieties

Au-Containing Coordination Polymers Based on Polyphosphorus Ligand Complexes

Whereas the self-assembly of pentaphosphaferrocenes [Cp$^R$Fe(η$^5$-P$_5$)] (Cp$^R$ = Cp*, Cp$^×$, and Cp$^{Bn}$) with Cu and Ag salts has been well-studied in the past, the coordination chemistry toward Au complexes has been left untouched so far. Herein, the results of the self-assembly processes of [Cp$^R$Fe($η^5$-P$_5$)] with Au salts of different anions (GaCl$_4$$^–$, SbF$_6$$^–$, and Al(OC(CF$_3$)$_3$)$_4$ (TEF$^–$)) are reported. Next to a variety of molecular coordination products, the first coordination polymers based on polyphosphorus ligand complexes and Au salts are also obtained. Thereby, a 2D coordination polymer comprising metal vacancies is isolated. In all products, the Au centers are coordinated in a linear or a trigonal planar environment. In solution, highly dynamic processes are observed. Variable-temperature NMR spectroscopy, solid-state NMR spectroscopy, and X-ray powder diffraction were applied to gain further insight into selected coordination compounds

Coordination Behavior of the 1,2,3-Triphosphaferrocene [Cp′′′Fe(η5-P3C2(H)Ph)] with Organometallic Moieties

The reaction of the 1,2,3-triphosphaferrocene [Cp′′′Fe(η5-P3C2(H)Ph)] (1) with the Lewis acidic complex [PtCl2(PEt3)]2 yields the monosubstituted derivative [Cp′′′Fe(η5-P3C2(H)Ph){PtCl2(PEt3)}] (2), in which the Pt moiety is located at the P atom adjacent to the C(H) group of the cyclo-P3C2 ring. Using an excess of the Pt complex no multiple substitution occurs. In contrast, using [W(CO)5] units as Lewis acids results in mono-, di-, and tricoordination at the cyclo-P3C2 ring. The products, [Cp′′′Fe(η5-P3C2(H)Ph){W(CO)5}n] (n = 1 (3), 2 (4), 3 (5)), have all been spectroscopically characterized, and the substitution patterns of the experimentally found (mono- and disubstituted) isomers are found to be in accordance with the energetically favored derivatives calculated by DFT methods. For these structures the energetically favored rotational conformers have also been calculated. The energetically favored 2,3-coordinated isomer 4b could be crystallized, and its structure and that of the tricoordinated derivative 5 were determined by X-ray diffraction methods