Komplexchemie P-reicher Phosphane und Silylphosphane. VII. Carbonylkomplexe des Heptaphosphans(3) iPr2(Me3Si)P7

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII Carbonyl Complexes of the Heptaphosphane(3) iPr₂(Me₃Si)P₇ From the reaction of iPr₂(Me₃Si)P₇ 1 with one equivalent of Cr(CO)₅THF the yellow products iPr₂(H)P₇[Cr(CO)₅] 2 and iPr₂(Me₃Si)P₇[Cr(CO)₅] 3 were isolated by column chromatography on silicagel. The P? H group in 2 results from a cleavage of the P? SiMe₃ bond during chromatography. The Cr(CO)₅ group in 2 is linked to an iPr? P^e atom, in 3 to the Me₃Si? P^e atom of the P₇ skeleton. The substituents do not force the formation of a single isomer; nevertheless 3 ist considerably favoured as compared to 2 . From the reaction of 1 with 2 equivalents of Cr(CO)₅THF the yellow iPr₂(H)P₇[Cr(CO)₅]₂ 4 was isolated bearing one Cr(CO)₅ group at an iPr? P^e atom, the other one at a P^b atom of the P₇ skeleton. Compound 3 yields with Cr(CO)₄NBD the red iPr₂(Me₃Si)P₇[Cr(CO)₅][Cr(CO)₄] 5 . Three isomers of 5 appear. Two P^e atoms of 5 are bridged by the Cr(CO)₄ group, the third P^e atom is linked to the Cr(CO)₅ ligand. iPr₂(H)P₇[Fe(CO)₄] was isolated from the reaction of 1 with Fe₂(CO)₉. ³¹P NMR and MS data are reported.     

Komplexchemie P-reicher Phosphane und Silylphosphane. XI [1]. Bildung,Reaktionen und Strukturen von Chromcarbonylkomplexen aus Reaktionen von Li(THF)2[η2-(tBu2P)2P] mit Cr(CO)5 · THF und Cr(CO)4 · NBD

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. XI. Formation, Reactions, and Structures of Chromium Carbonyl Complexes from Reactions of Li(THF)₂[η₂-(^tBu₂P)₂P] with Cr(CO)₅ · THF and Cr(CO)₄ · NBD Reactions of Li(THF)₂[η²-(^tBu₂P)₂P] 1 with Cr(CO)₅ · THF yield Li(THF)₂Et₂O[Cr(CO)₄{η²-(^tBu₂P)₂P}η¹-Cr(CO)₅] 2 and the compounds [Cr(CO)₄{η²-(^tBu₂P)₂PH}] 3 , [Cr(CO)₅{η¹-(^tBu₂P)₂PH}] 4 , (^tBu₂P)₂PH 5 and ^tBu₂PH · Cr(CO)₅ 6 . The formation of 3, 4, 5 and 6 is due to byproducts coming from the synthesis of 1. 2 reacts with CH₃COOH under formation of 3 . After addition of 12-crown-4 1 with NBD · Cr(CO)₄ in THF forms Li(12-crown-4)₂[Cr(CO)₄-{η²-(^tBu₂P)₂P}] 7 (yellow crystals). 7 reacts with CH₃COOH to 3 – which regenerates 7 with LiBu – with Cr(CO)₅THF to compound 2 , with NBD · Cr(CO)₄ in THF to 2 and 3 (ratio 1 : 1). With EtBr, 7 forms [Cr(CO)₄{η²-(^tBu₂P)₂PEt}] 8 , and [Cr(CO)₄{η²-(^tBu₂P)₂PBr}] 9 with BrCH₂? CH₂Br. The compounds were characterized by means of ¹H, ¹³C, ³¹P, ⁷Li NMR spectroscopy, IR spectroscopy, elementary analysis, mass spectra, and 2, 3 and 4 additionally by means of X-ray diffraction analysis. 2 crystallizes in the space group P1 with 2 formula units in the elementary cell; a = 10.137(9), b = 15.295(12), c = 15.897(14) Å; α = 101.82(7), β = 91.65(7), γ = 98.99(7)°; 3 crystallizes in the space group P2_t/n with 4 molecules in the elementary unit; a = 11.914(6), b = 15.217(10), c = 14.534(10) Å; α = 90, β = 103.56(5), γ = 90°. 4 : space group P1 with 2 molecules in the elementary unit; a = 8.844(4), b = 12.291(6), c = 14.411(7) Å, α = 66.55(2), β = 89.27(2), γ = 71.44(2)°.     

Komplexchemie P-reicher Phosphane und Silylphosphane. VII [1]. Bildung und Struktur von [Li(DME)3]2{(SiMe3)[Cr(CO)5]2 P?PP?P[Cr(CO)5]2(SiMe3)}

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII. Formation and Structure of [Li(DME)₃]₂{(SiMe₃)[Cr(CO)₅]₂ P-P ? P-P[Cr(CO)₅]₂(SiMe₃)} Deep red crystals of the title compound 1 are produced in the reaction of LiP(Me₃Si)₂[Cr(CO)₅] with 1, 2-dibromoethane in DME. The structure of 1 was derived from the investigation of the ³¹P-NMR spectra and confirmed by a single crystal structure determination. 1 crystallizes in the space group P1 (no. 2); a = 1307.8(5)pm, b = 1373.1(5)pm, c = 1236.1(4)pm, α = 106.22(4)°, β = 88.00(3)°, γ = 115.52(4)° and Z = 1. 1 forms a salt composed of a dianion R₂R₄′P₄^2? (R ? SiMe₃, R′ ? Cr(CO)₅) and solvated Li⁺ cations. The zigzag shaped dianion possesses the symmetry 1 -C_i. The distances d(P? P) = 202.5(1)pm and d(P? P) = 221.9(1)pm correspond to a double bond and single bonds, respectively. The distances d(Cr? P) = 251.1(1) pm and 255.3(1) pm are larger than those observed so far which might be caused by the charge distribution in the dianion.     

Komplexchemie P-reicher Phosphane und Silylphosphane. IV. Bildung und Struktur der Chromcarbonylkomplexe des Tris(di-tert-butylphospha)heptaphosphanortricyclans, (t-Bu2P)3P7

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. IV. Formation and Structure of the Chromium Carbonyl Complexes of Tris(di-tert-butylphospha)heptaphosphanortricyclane (t-Bu₂P)₃P₇ The reaction of (t-Bu₂P)₃P₇ 1 with Cr(CO)₅ · THF in a molar ratio of 1:1 yields yellow crystals of (t-Bu₂P)₃P₇[Cr(CO)₅] 2 having the Cr(CO)₅ group coordinated to a P^b atom (basal) of the three membered ring. With a molar ratio of 1:2 compounds 2 , (t-Bu₂P)₃P₇[Cr(CO)₅]₂ 3 , (t-Bu₂P)₃P₇[Cr(CO)₅][Cr(CO)₄] 4 and (t-Bu₂P)₃P₇[Cr(CO)₄]₂ 5 were obtained. In 3 (yellow crystals) one Cr(CO)₅ group is linked to a P^b atom, the other one to an exocyclic P^exo atom. On irradiation 3 loosing one CO group generates 4 (orange red crystals) with an unchanged Cr(CO)₅ group linked to the Pb atom and a five membered chelate-like ring containing an apical Pa atom, two equatorial P^a atoms, one P^exo atom and the Cr atom of the carbonyl group. Compound 5 (orange red crystals) contains two such five membered rings. (t-Bu₂P)₃P₇[Cr(CO)₄]₃ 6 (red needles) is formed with Cr(CO)₅ · THF in a molar ratio of 1 : 1. However, even with higher amounts of Cr(CO)₅ · THF and after extended reaction times, only 6 is formed; no further Cr carbonyl group could be attached to the P skeleton. With Cr(CO)₅ · NBD in a molar ratio of 1 : 1, (t-Bu₂P)₃P₇[Cr(CO)₄] 7 is produced from 1, and 5 with a molar ratio of 2 : 1. As in 4, the Cr(CO)₄ group in 7 (orange crystals) participates in a five membered chelate-like ring. It was not possible to generate 6 from 5 with an excess of Cr(CO)₄ · NBD and with extended reaction times. The molecular structures of the compounds were identified by investigating the ³¹P[¹H] NMR spec-tra and considering especially the coordination shift, and by crystal structure determinations of 2 and 4. Compound 2 crystallizes in the space group PI (no.2) with a = 1566.2(4) pm, b = 2304.1(5) pm, c = 1563.3(4) pm,α = 95.57(3)°, β = 108.79(3)°, γ = 109.82(4)° and Z = 4 formula units in the elementary cell. Compound 4 crystallizes in the space group P 2₁ /n (no. 14) with a = 1416.6(5) pm, b = 2573.6(5) pm, c = 1352.9(4) pm,β = 99.17(5)° and Z = 4 formula units in the elementary cell.     

Die Phosphide LiR2P7, Li2RP7 (R = Me3Si,Et, iPr,iBu) und alkyliert-silylierte Heptaphosphane(3)

The Phosphides LiR₂P₇, Li₂RP₇ (R = Me₃Si, Et, iPr, iBu) as well as Mixed Alkylated and Silylated Heptaphosphanes(3) Formation and properties of LiR₂P₇ and Li₂PR₇ (R = Me₃Si, Et, iPr, iBu) and their reactions with Me₃SiCl or alkylhalides yielding mixed alkylated and silylated heptaphosphanes(3) are reported. Reactions of (Me₃Si)₃P₇ and Li₃P₇. 3 DME produce mixtures of Li(Me₃Si)₃P₇, Li₂(Me₃Si)P₇ and Li₃P₇ from which pure Li(Me₃Si)₂P₇ (s, as) can be isolated by means of an extraction with toluene. Similarly, the isomers of LiR₂P₇ (R = Et, iPr, iBu) can be extracted from the mixtures obtained by reacting Li₃P₇ with alkylbromides. The (s) isomers of LiR₂P₇ in solution at about 20°C from the (as) isomers whereas the latter up to 70°C do not show any inversion. The (as) lithiumdialkylphosphides can be obtained as ether free products (red brown powder, isoluble in toluene, soluble in THF) by repeated addition of toluene and removal of the solvents; the (s) isomers decompose during the procure. In reactions of LiEt₂P₇. THF (s, as) in toluene at ?30°C with EtBr only the (s) isomer is substituted and gives Et₃P₇ (s), however on warming to 20°C by inversion of P^e a ratio of (s) : (as( = 1 : 3 is obtained. With Li(iBu)₂P₇, (s) reaction begins above ?20°C the giving both the (s) and the (as) isomer. (iBu)₃P₇ (s) is the prefered isomer at higher temperatures. Li(Me₃Si)₂P₇ (s, as) with Me₃SiCl exclusively yields (Me₃Si)₃P₇ (s). Li₂RP₇ (R = alkyl, Me₃SI) is not available. From mixtures with LiR₂P₇ and Li₃P₇, it can be isolated only after repeated cumbersome extraction of LiR₂P₇ as was shown with Li₂(iPr)P₇ as an example. Ether free LiEt₂P₇(s, as) with Me₃SiCl exclusively gives Et₂(Me₃Si)P₇ (s, as) whereas LiEt₂P₇ ? THF due to its THF content does not. Similarly, ether free Li(iBu)₂P₇ yields (iBu)₂(Me₃Si)P₇ (s, as). The compounds R(Me₃Si)₂P₇ (R = alkyl) cannot be selectively prepared neither starting from Li₂RP₇ with Me₃SiCI) nor from Li(Me₃Si)₂P₇ with RX. Such, the reaction of Li(Me₃Si)₂P₇ ? THF with EtBr in toluene at ?78°C yield a mixture of Et(Me₃Si)₂P₇ (42%), Et₂(Me₃Si)P₇ (27010), (Me₃Si)₃P₇ (29%) and Et₃P₇ (2%). (Me₃Si)₃P₇ with MeI in a molar ratio of 1 : 1 at 70°C quantitatively produces Me(Me₃Si)₂P₇ whereas already using a molar ratio of 1 : 2 also Me₃P₇ is obtained. With EtBr mixtures of Et(Me₃Si)₂P₇ and Et₃P₇ are formed. iBuBr gives iBu₃P₇, but tBuBr does not yield any tBu₃P₇.     

Komplexchemie P-reicher Phosphane und Silylphosphane. X [1] Zum Einfluß der Komplexierung auf die Reaktivität des [(Me3Si)2P]2PH

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. X. The Influence of the Formation of Complex Compounds on the Reactivity of [(Me₃Si)₂P]₂PH Whereas [(Me₃Si)₂P]₂PH 1 by BuLi is attacked at the PH group to give [(Me₃Si)₂P]₂PLi 2 , the related chromium carbonyl complex (Me₃Si)P^IV ? ²P^IV(H) ? ³P^III(Si? Me₃)₂ · Cr(CO)₄ 3 with BuLi yields Li(Me₃Si)¹P^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂ · Cr(CO)₄ 4 by cleaving a Si? P bond at the chromium substituted ¹P atom. Dissolved in ether, 4 is stable for a longer time, while under comparable conditions 2 forms Li₃P₇ which is not obtained from 4 . MeOH in 3 cleaves selectively the Me₃Si groups from the complex substituted P atom yielding (Me₃Si)(H)¹P^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂ · Cr(CO)₄ 5 and HP^IV ? ²P^IV(H) ? ³P^III(SiMe₃)₂Cr(CO)₄ 6. 5 and 6 seem to be stable in contrast to the uncoordinated triphosphanes which are not known.     

Clusteraufbau durch Photolyse von R3PAuN3. VIII. Synthese und Kristallstruktur von [(Ph3PAu)5Mo(CO)4]PF6 · CH2Cl2 und (Ph3PAu)3Co(CO)3

Cluster Synthesis by Photolysis of R₃PAuN₃. VIII. Synthesis and Crystal Structure of [(Ph₃PAu)₅Mo(CO)₄]PF₆ · CH₂Cl₂ and (Ph₃PAu)₃Co(CO)₃ Photolysis of a mixture of Ph₂PAuN₃ and Mo(CO)₆ in THF yields [(Ph₃PAu)₅Mo(CO)₄]⁺ (1), which can be crystallized from CH₂Cl₂/diisopropylether as orange 1 · PF₆ · CH₂Cl₂ with the space group P2₁/c and a = 1681.4(5), b = 2215.6(12), c = 2761.5(9) pm, β = 91.54(3)°, Z = 4. The Au₅Mo center of cluster 1 forms a capped trigonal bipyramid with the Mo atom in equatorial position and almost equal Mo? Au distances between 279.9(5) and 284.6(7) pm to all five Au atoms. The Au? Au distances range from 272.2(4) to 301.3(4) pm. The Mo(CO)₄ group causes three v(C0) at 1975, 1915 and 1890cm^?1. Reaction of Ph₃PAuCo(CO)₄ with Ph₃PAuPF₆ affords the known cluster cation [(Ph₃PAu)₄Co(CO)₃]⁺ in high yield. It can be degraded with C1^? to the neutral cluster (Ph₃PAu)₃Co(CO)₃ (2). 2 forms air stable, yellow crystals with the space group P2₁/n and a = 1359.4(4), b = 2041.0(5), c = 1853.2(6)pm, β = 91.47(1)°, Z = 4. The Au₃Co core of 2 has a tetrahedral structure with distances Co? Au between 250.4(1) and 254.0(2) pm and Au? Au between 279.5(1) and 285.1(1) pm. v(C0) are observed at 1963, 1905 and 1891 cm^?1. Reaction of 2 with [(Ph₃PAu)₄Co(CO)₃]⁺ yields the condensed cluster [(Ph₃PAu)₆AuCo₂(CO)₆]⁺.     

Die Ammonolyse von (NH4)2GeF6. Darstellung und Struktur von NH4[Ge(NH3)F5]

Ammonolysis Reaction of (NH₄)₂GeF₆. Synthesis and Structure of NH₄[Ge(NH₃)F₅] (NH₄)₂GeF₆ reacts with ammonia to yield NH₄[Ge(NH₃)F₅] at 280°C. The reaction path was elucidated by in situ time and temperature resolved X-ray powder diffraction. NH₄[Ge(NH₃)F₅] crystallizes isostructurally to NH₄[Si(NH₃)F₅] in the tetragonal space group P4/n (No. 85) with lattice constants a = 619.41(1) pm and c = 724.70(1) pm. The germanium atom is coordinated by five fluorine atoms and the nitrogen atom of the ammonia molecule. The ammonium cation is located on the Wyckoff position (2 a) in P4/n. The crystal structure is stabilized by extensive hydrogen bonding.     

Synthese und Kristallstrukturen von (Ph4P)4[Bi8I28], (nBu4N)[Bi2I7] und (Et3PhN)2[Bi3I11] – Iodobismutate mit isolierten bzw. polymeren Anionen

Synthesis and Crystal Structures of (Ph₄P)₄[Bi₈I₂₈], (ⁿBu₄N)[Bi₂I₇], and (Et₃PhN)₂[Bi₃I₁₁] – Bismuth Iodo Complexes with Isolated and Polymeric Anions Solutions of BiI₃ in methanol react with NaI and (ⁿBu₄N)(PF₆) or (Et₃NPh)(PF₆) to form anionic bismuth iodo complexes (ⁿBu₄N)[Bi₂I₇] 1 and (Et₃PhN)₂[Bi₃I₁₁] 2 . In 1 Bi₄I₁₆ units, and in 2 Bi₆I₂₄ units are linked by common I-atoms to onedimensional infinite chains. Reaction of BiI₃ with (Ph₄P)(PF₆) in methanol yields (Ph₄P)₄[Bi₈I₂₈] 3 . The anions of 1–3 consist of edge-sharing BiI₆ octahedra. (ⁿBu₄N)[Bi₂I₇] 1 : Space group I2/m (No. 13), a = 1 082.3(5), b = 2 597.1(13), c = 1 206.1(6) pm, β = 93.17(2)°, V = 3 385(3) · 10⁶ pm³; (Et₃PhN)₂[Bi₃I₁₁] 2 : Space group P1 (No. 2), a = 1 283.5(6), b = 1 345.9(7), c = 1 546.3(8) pm, α = 83.87(2), β = 74.24(2), γ = 68.26(2)°, V = 2 388(2) · 10⁶ pm³; (Ph₄P)₄[Bi₈I₂₈] 3 : Space group P1 (No. 2), a = 1 329.3(4), b = 1 337.0(4), c = 2 193.1(5) pm, α = 104.20(2), β = 99.73(2), γ = 100.44(2)°, V = 3 622(2) · 10⁶ pm³.     

Reaktionen des [η2-{P–PtBu2}Pt(PPh3)2] und [η2-{P–PtBu2}Pt(dppe)] mit Metallcarbonylen. Bildung von [η2-{(CO)5M · PPtBu2}Pt(PPh3)2] (M = Cr,W) und [η2-{(CO)5Cr · PPtBu2}Pt(dppe)]

Coordination Chemistry of P-rich Phosphanes and Silylphosphanes. XVI [1] Reactions of [g²-{P–P^tBu₂}Pt(PPh₃)₂] and [g²-{P–P^tBu₂}Pt(dppe)] with Metal Carbonyls. Formation of [g²-{(CO)₅M · PP^tBu₂}Pt(PPh₃)₂] (M = Cr, W) and [g²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] [η²-{P–P^tBu₂}Pt(PPh₃)₂] 4 reacts with M(CO)₅ · THF (M = Cr, W) by adding the M(CO)₅ group to the phosphinophosphinidene ligand yielding [η²-{(CO)₅Cr · PP^tBu₂}Pt(PPh₃)₂] 1 , or [η²-{(CO)₅W · PP^tBu₂}Pt(PPh₃)₂] 2 , respectively. Similarly, [η²-{P–P^tBu₂}Pt(dppe)] 5 yields [η²-{(CO)₅Cr · PP^tBu₂}Pt(dppe)] 3 . Compounds 1 , 2 and 3 are characterized by their ¹H- and ³¹P-NMR spectra, for 2 and 3 also crystal structure determinations were performed. 2 crystallizes in the monoclinic space group P2₁/n (no. 14) with a = 1422.7(1) pm, b = 1509.3(1) pm, c = 2262.4(2) pm, β = 103.669(9)°. 3 crystallizes in the triclinic space group P1 (no. 2) with a = 1064.55(9) pm, b = 1149.9(1) pm, c = 1693.2(1) pm, α = 88.020(8)°, β = 72.524(7)°, γ = 85.850(8)°.     

Synthese,Charakterisierung und Struktur von P7(t-Bu3Si)3 („Tris(supersilyl)heptaphosphan(3)”︁)

Synthesis, Characterization, and Structure of P₇(t-Bu₃Si)₃ (?Tris(supersilyl)heptaphosphane(3)”? Tris(tri-tert-butylsilyl)heptaphosphanortricyclane P₇(t-Bu₃Si)₃ 1 is obtained from the reaction of (t-Bu)₃Si? Si(t-Bu)₃ with white phosphorus and forms colorless to pale yellow thermostable crystals. 1 is identified by the complete analysis of its ³¹P{¹H} NMR spectrum (A[MX]₃ spin system) as well as by a single crystal structure determination (space group Pca2₁, a = 170.76(2)pm, b = 131.14(3)pm, c = 426.61(5)pm, α = β = γ= 90°, Z = 8 formula units in the elementary cell). The steric demand of the (t-Bu)₃Si-Groups causes an increase of the exocyclic bond angles at the equatorial phosphorus atoms P^e, while it does not particularly influence the P₇-skeleton. Chlorine (r.t.) and bromine (70°C) degrade the P₇-cage of 1 with formation of PX₃ and (t-Bu)₃SiX (X = Cl, Br).     

Komplexchemie P-reicher Phosphane und Silylphosphane. VIII. Zur unterschiedlichen Tendenz der Bildung von Chromcarbonyl-Komplexen silylierter-alkylierter Phosphane und Diphosphane

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VIII. Concerning the Different Tendencies of Silylated and Alkylated Phosphanes and Diphosphanes to Form Chromium Carbonyl Complexes The influence of the substituents Me₃Si tBu and Me in phosphanes and diphosphanes on the formation of complex compounds with Cr(CO)₅THF is investigated. tBu(Me₃Si)P? P(SiMe₃)₂ 1 and (tBu)₂P? P(SiMe₃)₂ 2, resp., react with Cr(CO)₅THF 4 at ?18°C by coordinating Cr(CO)₅ to the P(SiMe₃)₂ group to give tBu(Me₃Si)P? P^IV(SiMe₃), · Cr(CO)₅ 1 a, tBu(Me₃Si)P^IV? P^IV(SiMe₃)₂ · Cr(CO)₄ 1b and (tBu)₂P? P^IV(SiMe₃)₂ · Cr(CO)₅ 2a . In the reaction of 1 with 4 using a molar ratio of 1:2 at first 1 a is formed which reacts on to yield completely 1 b. In a mixture of the dissolved compounds (Me₃Si)₃P 5, (tBu)₃P 6 and (tBu)₃P? P(SiMe₃)₂ 2 only 5 and 6 react with Cr(CO)₅THF yielding (Me₃Si)₃P · Cr(CO)₅ and (tBu)₃P · Cr(CO)₅, but 2 does not yet react. In a solution of (Me₃Si)₃P 5, P₂Me₄ 7 and (Me₃Si)₂P? PMe₂ 3 only 5 and 7 react with Cr(CO)₅THF (0.25 to 1.5 equivalents with respect to 3) to give (Me₃Si)₃P · Cr(CO)₅, P₂Me₄ · Cr(CO)₅ and P₂Me₄ · 2Cr(CO)₅. The formation of complexes with Cr(CO)₅THF of the phosphanes 5 and 6 is clearly favoured as compared to the silylated diphosphanes 2 and 3 (not to P₂Me₄); the PR₂ groups (R = tBu, Me in 2 or 3 ) don't have a strong influence.     

Effect of External Pressure on the Excitation Energy Transfer from [Cr(ox)3]3− to [Cr(bpy)3]3+ in [Rh1−xCrx(bpy)3][NaM1−yCry(ox)3]ClO4

Resonant excitation energy transfer from [Cr(ox)₃]^3? to [Cr(bpy)₃]³⁺ in the doped 3D oxalate networks [Rh_1?xCr_x(bpy)₃][NaM^III_1?yCr_y(ox)₃]ClO₄ (ox=C₂O₄^?, bpy=2,2′‐bipyridine, M=Al, Rh) is due to two types of interaction, namely super exchange coupling and electric dipole–dipole interaction. The energy transfer probability for both mechanisms is proportional to the spectral overlap of the ²E→⁴A₂ emission of the [Cr(ox)₃]^3? donor and the ⁴A₂→²T₁ absorption of the [Cr(bpy)₃]³⁺ acceptor. The spin‐flip transitions of (pseudo‐)octahedral Cr³⁺ are known to shift to lower energy with increasing pressure. Because the shift rates of the two transitions in question differ, the spectral overlap between the donor emission and the acceptor absorption is a function of applied pressure. For [Rh_1?xCr_x(bpy)₃][NaM_1?yCr_y(ox)₃]ClO₄ the spectral overlap is thus substantially reduced on increasing pressure from 0 to 2.5 GPa. As a result, the energy transfer probability decreases with increasing pressure as evidenced by a decrease in the relative emission intensity from the [Cr(bpy)₃]³⁺ acceptor.     

Clusteraufbau durch Photolyse von Azidokomplexen des Platins und Golds. Synthesen und Kristallstrukturen von [(Ph3PAu)6(AuCl)3Pt(CO)], [(dppe)PtCo2(CO)7] und [(Ph3PAu)4Pt(dppe)](PF6)2

Cluster Synthesis by Photolysis of Azido Complexes of Platinum and Gold. Syntheses and Crystal Structures of [(Ph₃PAu)₆(AuCl)₃Pt(CO)], [(dppe)PtCo₂(CO)₇] and [(Ph₃PAu)₄Pt(dppe)](PF₆)₂ Photolysis of a mixture of Ph₃PAuN₃, Ph₃PAuCl and (Ph₃P)₂Pt(N₃)₂ in THF yields after chromatographic separation with CH₂Cl₂/EtOH as eluens the cluster [(Ph₃PAu)₆(AuCl)₃Pt(CO)] ( 1 ). It crystallizes in the triclinic space group P1 with the lattice parameters a = 2 139.3(4), b = 2 457.1(4), c = 2 561.9(1) pm, α = 79.74(9)°, β = 80.06(6)°, γ = 66.05(5)°, Z = 4. The nine gold atoms form a fragment of an icosahedron with the platinum atom in its center. Upon photolysis of (dppe)Pt(N₃)₂ with Co₂(CO)₈ in THF one m?₂-CO ligand of the cobalt carbonyl is substituted by a (dppe)Pt group. The resulting cluster [(dppe)PtCo₂(CO)₇] ( 2 ) crystallizes monoclinically in the space group P2₁/n with a = 1 303.9(3), b = 1 768.1(8), c = 1 461.4(4) pm, β = 102.81(1)°, Z = 4. Photolysis of 2 with excess Ph₃PAuN₃ affords the clusters [(Ph₃PAu)₄Pt(dppe)]²⁺ ( 3 ), and [(Ph₃PAu)₆AuCo₂(CO)₆]⁺. 3 crystallizes with PF as counterions in the triclinic space group P1 with a = 1 369.1(4), b = 1 505.0(4), c = 2 773.0(8) pm, α = 84.74(1)°, β = 87.37(2)°, γ = 65.94(2)°, Z = 2. The Au₄Pt skeleton of 3 forms a trigonal bipyramid with the platinum atom in equatorial position.     

Zweikernige silylenverbrückte Cyclopentadienylrhodiumbis(ethen)-Komplexe,photochemische Reaktion mit Benzolderivaten und selektiver Einschluß von Methylcyclopentan in das Kristallgitter von [Me2Si{3-But-C5H3Rh(C2H4)2}2]

Dinuclear Silylene Bridged Cyclopentadienylrhodiumbis(ethene) Complexes, Photochemical Reaction with Benzene Derivatives, and Selective Inclusion of Methylcyclopentane into the Crystal Lattice of [Me₂Si{3-Bu^t-C₅H₃Rh(C₂H₄)₂}₂] By reaction of [{(C₂H₄)₂RhCl}₂] with Na₂[Me₂Si(C₅H₄)₂] or with Li₂[Me₂Si(3-Bu^t-C₅H₃)₂] in THF the dinuclear silylene bridged complexes [Me₂Si{C₅H₄Rh(C₂H₄)₂}₂] 1 and [Me₂Si{3-Bu^t-C₅H₃Rh(C₂H₄)₂}₂] 2 , respectively, were synthesized. Due to the asymmetric substitution of the five-membered rings and their hindered rotation around the Si? C axes, 2 is formed as three isomers. The X-ray structure analysis of 2 obtained from hexane reveals the selective inclusion of methylcyclopentane, the content of which in the solvent is about 17%, into the crystal lattice. UV irradiation of 1 in hexane in the presence of benzene causes elimination of the ethene ligands yielding the μ-η³:η³ benzene complex [Me₂Si(C₅H₄Rh₂)₂C₆H₆] which cannot be separated from unreacted 1 . However, separation is possible in case of the hexamethylbenzene compound 4 analogous with 3 .     

[t-Bu2P]3P7 und (t-Bu2Sb)3P7 sowie Untersuchungen zur Bildung von Heptaphosphanen(3) mit PMe2-, PF2- und P(CF3)2-Gruppen

[t-Bu₂P]₃P₇ and (t-Bu₂Sb)₃P₇, as well as Investigations on the Formation of Heptaphosphanes (3) Containing PMe₂, PF₂, and P(CF₃)₂ Groups Tris(di-tert-butylphospha)heptaphosphanortricyclane (t-Bu₂P)₃P₇ 1 obtained by reacting Li₃P₇ · 3 DME with t-Bu₂PF forms yellow crystals. (t-Bu₂Sb)₃P₇ 2 produced similarly from t-Bu₂SbCl and Li₃P₇ · 3 DME didn't form crystals; it decomposes in a solution of toluene above ?10°C. Both compounds were identified by their ³¹P{¹H} NMR spectra, and 1 also by elemental analysis and single crystal structure determination (space group) P2₁/a, a = 1 712.0(9) pm, b = 1 105.1(7) pm, c = 1 854.0(10) pm, β = 94.96(4)°, Z = 4 formula units in the elementary cell). Attempts to synthesize (Me₂P)₃P₇ 3 , (F₂P)₃P₇ 4 and [(F₃C)₂P]₃P₇ 5 failed as dialkylchlorophosphanes as Me₂PCl e. g. with Li₃P₇ · 3 DME react under Li/Cl exchange, dialkylfluorophosphanes (except t-Bu₂PF) disproportionate, and neither PF₃ nor (F₃C)₂PBr with Li₃P₇ · 3 DME give the desired products 4 or 5 , resp.     

[Mg3Cl5(Et2O)6]+: Darstellung,Strukturbestimmung und ab-initio-Untersuchungen

[Mg₃Cl₅(Et₂O)₆]⁺: Synthesis, Structure, and Ab-Initio Calculations The cation [Mg₃Cl₅(Et₂O)₆]⁺ of a chlorogallat has been prepared in a reaction of Ga₂Cl₄ with MgCp and was characterized by a X-ray single-crystal structure analysis. For understanding of the conditions of formation of neutral and charged magnesium chlorids and of the processes in the complex reaction system ab-initio calculations were performed.     

Reaktionen von Cyclostibanen (RSb)n [R = (Me3Si)2CH,n = 3; Me3CCH2, n = 4, 5] mit den Übergangsmetallcarbonyl‐Komplexen [W(CO)5(thf)], [CpxMn(CO)2(thf)], [CpxCr(CO)3]2 und [Co2(CO)8]; Cpx = MeC5H4

Reactions of Cyclostibanes, (RSb)_n [R = (Me₃Si)₂CH, n = 3; Me₃CCH₂, n = 4, 5] with the Transition Metal Carbonyl Complexes [W(CO)₅(thf)], [Cp^xMn(CO)₂(thf)], [Cp^xCr(CO)₃]₂, and [Co₂(CO)₈]; Cp^x = MeC₅H₄ (RSb)₃ [R = (Me₃Si)₂CH] reacts with [W(CO)₅(thf)], [Cp^xMn(CO)₂(thf)], or [Co₂(CO)₈] to give [(RSb)₃W(CO)₅] ( 1 ), [RSb{Mn(CO)₂Cp^x}₂] ( 2 ) or [RSbCo(CO)₃]₂ ( 3 ). The reaction of (R′Sb)_n (n = 4, 5; R′ = Me₃CCH₂) with [Cp^xCr(CO)₃]₂ leads to [(R′Sb)₄{Cr(CO)₂Cp^x}₂] ( 4 ); Cp^x = MeC₅H₄, thf = Tetrahydrofuran.     

Darstellung,Strukturen und Eigenschaften von Tris-hexamethyl-trisila-tetraphospha-nortricyclen-bis-chromtricarbonyl [P4(Sime2)3]3[Cr(CO)3]2

Preparation, Structures, and Properties of Tris-hexamethyl-trisila-tetraphospha-nortricyclene-bis-chromiumtricarbonyl [P₄(Sime₂)₃]₃[Cr(CO)₃]₂ Hexamethyl-trisila-tetraphospha-nortricyclene P₄(Sime₂)₃ 1 reacts with C₆H₆Cr(CO)₃ or (CHT)Cr(CO)₃ (CHT ? Cycloheptatriene) under formation of [P₄(Sime₂)₃]₃[Cr(CO)₃]₂ 3 (red crystals), in which each of the Cr atoms is attached to one P atom of a P₃ ring of the three molecules 1 . 3 can also be prepared by heating a solution of P₄(Sime₂)₃Cr(CO)₅ in benzene or THF up to 120–1307deg;C. The compound 3 crystallizes in an orthorhombic and a hexagonal form, the latter being stabilized by one mole toluene. As revealed by single crystal investigations, the symmetry ¯6, distances and angles are nearly unchanged. The o-form corresponds to a face centered cubic packing of the molecules, whereas the h-form is hexagonal close packed.     

Darstellung und Strukturen von (Et4N)2[Re(CO)3(NCS)3] und (Et4N)[Re(CO)2Br4]

Syntheses and Structures of (Et₄N)₂[Re(CO)₃(NCS)₃] and (Et₄N)[Re(CO)₂Br₄] Rhenium(I) and rhenium(III) carbonyl complexes can easily be prepared by ligand exchange reactions starting from (Et₄N)₂[Re(CO)₃Br₃]. Using nonoxidizing reagents the facial Re^I(CO)₃ unit remains and only the bromo ligands are exchanged. Following this procedure, (Et₄N)₂[Re(CO)₃(NCS)₃] can be obtained in high yield and purity using trimethylsilylisothiocyanate. The compound crystallizes in the monoclinic space group P2₁/n, a = 18.442(5), b = 17.724(3), c = 18.668(5) Å, β = 92.54(1)°, Z = 8. The NCS^? ligands are coordinated via nitrogen. The reaction of [Re(CO)₃Br₃]^2? with Br₂ yields the rhenium(III) anion [Re(CO)₂Br₄]^?. The tetraethylammonium salt of this complex crystallizes in the noncentrosymmetric, orthorhombic space group Cmc2₁, a = 8.311(1), b = 25.480(6), c = 8.624(1) Å, Z = 4. The carbonyl ligands are positioned in a cis arrangement. Their strong trans influence causes a lengthening of the Re? Br bond distances by at least 0.05 Å.