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.

Reactivity of E4 (E4 =P4 , As4 , AsP3 ) towards Low-Valent Al(I) and Ga(I) Compounds.

The reactivity of yellow arsenic and the interpnictogen compound AsP3 towards low-valent group 13 compounds was investigated. The reactions of [LAl] (1, L=[{N(C6 H3 i Pr2 -2,6)C(Me)}2 CH]- ) with As4 and AsP3 lead to [(LAl)2 (µ,η1:1:1:1 -E4 )] (E4 =As4 (3 b), AsP3 (3 c)) by insertion of two fragments [LAl] into two of the six E-E edges of the E4 tetrahedra. Furthermore, the reaction of [LGa] (2) with E4 afforded [LGa(η1:1 -E4 )] (E4 =As4 (4 b), AsP3 (4 c)). In these compounds, only one E-E bond of the E4 tetrahedra was cleaved. These compounds represent the first examples of the conversion of yellow arsenic and AsP3 , respectively, with group 13 compounds. Furthermore, the reactivity of the gallium complexes towards unsaturated transition metal units or polypnictogen (En ) ligand complexes was investigated. This leads to the heterobimetallic compounds [(LGa)(µ,η2:1:1 -P4 )(LNi)] (5 a), [(Cp'''Co)(µ,η4:1:1 -E4 )(LGa)] (E=P (6 a), As (6 b), Cp'''=η5 -C5 H2 t Bu3 ) and [(Cp'''Ni)(η3:1:1 -E3 )(LGa)] (E=P (7 a), As (7 b)), which combine two different ligand systems in one complex (nacnac and Cp) as well as two different types of metals (main group and transition metals). The products were characterized by crystallographic and spectroscopic methods.

Binding, Release and Functionalization of Intact Pnictogen Tetrahedra Coordinated to Dicopper Complexes.

The bridging MeCN ligand in the dicopper(I) complexes [(DPFN)Cu2 (µ,η1 : η1 -MeCN)][X]2 (X=weakly coordinating anion, NTf2 (1 a), FAl[OC6 F10 (C6 F5 )]3 (1 b), Al[OC(CF3 )3 ]4 (1 c)) was replaced by white phosphorus (P4 ) or yellow arsenic (As4 ) to yield [(DPFN)Cu2 (µ,η2 : η2 -E4 )][X]2 (E=P (2 a-c), As (3 a-c)). The molecular structures in the solid state reveal novel coordination modes for E4 tetrahedra bonded to coinage metal ions. Experimental data and quantum chemical computations provide information concerning perturbations to the bonding in coordinated E4 tetrahedra. Reactions with N-heterocyclic carbenes (NHCs) led to replacement of the E4 tetrahedra with release of P4 or As4 and formation of [(DPFN)Cu2 (µ,η1 : η1 -Me NHC)][X]2 (4 a,b) or to an opening of one E-E bond leading to an unusual E4 butterfly structural motif in [(DPFN)Cu2 (µ,η1 : η1 -E4 Dipp NHC)][X]2 (E=P (5 a,b), E=As (6)). With a cyclic alkyl amino carbene (Et CAAC), cleavage of two As-As bonds was observed to give two isomers of [(DPFN)Cu2 (µ,η2 : η2 -As4 Et CAAC)][X]2 (7 a,b) with an unusual As4 -triangle+1 unit.

Triple-decker complexes incorporating three distinct deck architectures.

The reactivity of the dilithioplumbole ([Li2(thf)2(µ,η5-LPb)], LPb = 1,4-bis-tert-butyl-dimethylsilyl-2,3-bis-phenyl-plumbolyl) towards the reactive pnictogen precursors P4, pentaphosphaferrocene, and pentaarsaferrocene ([Cp*Fe(η5-E5)] (Cp* = η5-C5Me5, E = P, As)) is reported. The reaction with P4 afforded a phospholyl lithium complex, via lead-phosphorus exchange, while the reactions with [Cp*Fe(η5-E5)] yielded the first examples of Pb-Fe-Li heterotrimetallic triple-decker polypnictogenides with three different deck motifs.

Conversion of E4 (E4 =P4 , As4 , AsP3 ) by Ni(0) and Ni(I) Synthons - A Comparative Study.

The reactivity of white phosphorus and yellow arsenic towards two different nickel nacnac complexes is investigated. The nickel complexes [(L1 Ni)2 tol] (1, L1 =[{N(C6 H3 i Pr2 -2,6)C(Me)}2 CH]- ) and [K2 ][(L1 Ni)2 (µ,η1 : 1 -N2 )] (6) were reacted with P4 , As4 and the interpnictogen compound AsP3 , respectively, yielding the homobimetallic complexes [(L1 Ni)2 (µ-η2 ,κ1 :η2 ,κ1 -E4 )] (E=P (2 a), As (2 b), AsP3 (2 c)), [(L1 Ni)2 (µ,η3 : 3 -E3 )] (E=P (3 a), As (3 b)) and [K@18-c-6(thf)2 ][L1 Ni(η1 : 1 -E4 )] (E=P (7 a), As (7 b)), respectively. Heating of 2 a, 2 b or 2 c also leads to the formation of 3 a or 3 b. Furthermore, the reactivity of these compounds towards reduction agents was investigated, leading to [K2 ][(L1 Ni)2 (µ,η2 : 2 -P4 )] (4) and [K@18-c-6(thf)3 ][(L1 Ni)2 (µ,η3 : 3 -E3 )] (E=P (5 a), As (5 b)), respectively. Compound 4 shows an unusual planarization of the initial Ni2 P4 -prism. All products were comprehensively characterized by crystallographic and spectroscopic methods.

Reactivity of Cu(I) Nacnac Complexes Toward Polypnictogen Compounds.

The nacnac Cu(I) compound [LCu(MeCN)] (2) (L = [{N(C6H3Me2-2,6)C(Me)}2CH]-) was reacted with complexes containing aromatic cyclo-E5 ([Cp*Fe(η5-E5)], E = P (1a), As (1b), Cp* = η5-C5Me5), cyclo-P4 ([Cp‴Co(η4-P4)] (3), Cp‴ = η5-C5H2tBu3) and cyclo-E3 ligands ([Cp‴Ni(η3-E3)], E = P (4a), As (4b)) yielding the heterometallic complexes [(Cp*Fe)(µ,η5:2-E5)(LCu)] (E = P (5a), As (5b)), [(Cp*Fe)(µ3,η5:2:1-E5)(LCu)2] (E = P (6a), As (6b)), [(Cp‴Co)(µ,η4:2-P4)(LCu)] (7), [(Cp‴Co)(µ3,η4:2:1-P4)(LCu)2] (8), and [(Cp‴Ni)(µ,η3:2-E3)(LCu)] (E = P (9a), As (9b)). These complexes are rare examples of the coordination of a group 11 metal to aromatic cyclo-En (E = P, As; n = 3-5) ligands. All products were comprehensively characterized by crystallographic and spectroscopic methods. Their dynamic behavior in solution was studied by VT (variable-temperature) NMR spectroscopy, and their electronic structures were elucidated by DFT calculations.

Measurement of immature platelets with Abbott CD-Sapphire and Sysmex XE-5000 in haematology and oncology patients.

BACKGROUND: Measurement of immature platelets was introduced into routine diagnostics by Sysmex as immature platelet fraction (IPF) some years ago and recently by Abbott as reticulated platelet fraction (rPT). Here, we compare both methods. METHODS: We evaluated the precision and agreement of these parameters between Sysmex XE-5000 and Abbott CD-Sapphire in three distinct thrombocytopaenic cohorts: 30 patients with beginning thrombocytopaenia and 64 patients with recovering platelets (PLT) after chemotherapy, 16 patients with immune thrombocytopaenia (ITP) or heparin-induced thrombocytopaenia type 2 (HIT) and 110 additional normal controls. Furthermore, we analysed, how IPF/rPT differed between these thrombocytopaenic cohorts and controls. RESULTS: Both analysers demonstrated acceptable overall precision (repeatability) of IPF/rPT with lower precision at low PLT counts. IPF/rPT artificially increased during storage of blood samples overnight. Inter-instrument comparison showed a moderate correlation (Pearson r²=0.38) and a systematic bias of 1.04 towards higher IPF-values with the XE-5000. IPF/rPT was highest in recovering thrombopoesis after chemotherapy and moderately increased in ITP/HIT. The normal range deduced from control samples was much narrower with CD-Sapphire (1.0%-3.8%, established here for the first time) in comparison to XE-5000 (0.8%-7.9%) leading to a smaller overlap of samples with increased PLT turnover and normal controls. CONCLUSIONS: IPF and rPT both give useful information on PLT turnover, although the two analysers only show a moderate inter-instrument correlation and have different reference ranges. A better separation of patient groups with high PLT turnover like ITP/HIT from normal controls is obtained by CD-Sapphire.