Phosphoraniminato Complexes Research Articles

Neues aus der Chemie des Berylliums

AbstractRecent Advances in the Chemistry of BerylliumA review of recent results in coordination chemistry of beryllium halides is given. In accordance with the editors' objective, this Research Report is not a complete review of the literature in this field, but the important literature close to it is considered. The following subjects are presented:(i) Syntheses and structural characterizations of tetraphenylphosphonium salts of [BeCl4]2−, [Be2Cl6]2−, and the unique [Be2F6]2− ion, which are soluble in organic solvents like dichloromethane or acetonitrile. (Ph4P)2[Be2F6]·2CH3CN is also extensively studied by IR spectroscopy and quantum chemical calculations (DFT).(ii) Application of (Ph4)2[Be2Cl6] to prepare donor acceptor complexes with N‐donor ligands D to give complexes [BeCl3(D)]− which are isoelectronical with the corresponding boron compounds [BCl3(D)], including quantum chemical calculations.(iii) Molecular complexes of the type [BeCl2(D)2] with D = phosphorane imines HNPR3 or Me3SiNPR3.(iv) Phosphoraneiminato complexes of beryllium, among these the first example [BeCl(μ‐NPEt3)]4 with a Be4N4 heterocubane skeleton.(v) Azido complexes of several types, including the unique examples with adamantane‐like structure [Be4X4(μ‐N3)6]2− with X = Cl, Br.(vi) Monocationic complexes [BeCl(12‐crown‐4)]+[SbCl4]− and [BeCl(PMDETA)]+Cl− (PMDETA = pentamethyl‐diethylenetriamine).(vii) Dicationic complexes with O‐donor ligands H2O and OSMe2. [Be(OH2)4]Cl2, [Be(OSMe2)4]Cl2, and mixed ligand complexes like [Be(OH2)2(OSMe2)2]Cl2.(viii) Molecular and anionic oxo‐complexes, particularly with μ‐OSiMe3 groups, among these the tetramethyl‐trioxosilanato complex (Ph4P)2[Be4(μ‐Cl)2Cl4(OSiMe2OSiMe2O)2].

Reactions of Transition Metal Azido Complexes and their Reaction Products

AbstractTransition metal azido complexes can undergo various reactions of their azido group to yield interesting products. The cleavage of the Naα‐Nβ bond and elimination of molecular nitrogen can generate nitrido complexes like MoNCl3 or WNCl3, chloroiminato complexes like Cl3VNCl, or phosphoraneiminato complexes like [Cl4NbNPPh3]2 with metal nitrogen multiple bonds. The reductive elimination of the complete azido group on the other hand may produce metal(0) fragments which in case of gold(I) azido complexes can combine to form clusters.

Synthese und Struktur von [(Ph3PAu)3NPPh3][PF6]2, einem Gold(I)-phosphoraniminato-Komplex

Synthesis and Crystal Structure of [(Ph3PAu)3NPPh3][PF6]2, a Gold(I) Phosphoraneiminato Complex The photolytic reaction of Ph3PAuN3 with Cr(CO)6 in THF yields the phosphoraneiminato complex [(Ph3PAu)3NPPh3]2+ in low yield as well as the cluster cation [(Ph3PAu)8]2+ as the main product. The phosphoraneiminato complex crystallizes from CH2Cl2 with [PF6]− ions as [(Ph3PAu)3NPPh3][PF6]2·CH2Cl2 in the triclinic space group with a = 1200.8(1), b = 1495.6(2), 2053.5(5), α = 86.97(2)°, β = 82.79(1)°, γ = 81.87(2)°, and Z = 2. The phosphoraneiminato ligand bridges through its N atom three Au atoms, which itself are connected to each other by weak aurophilic interactions.

Oxidative Addition von N‐Chlortriphenylphosphanimin an Phosphortrichlorid und Antimontrichlorid. Kristallstrukturen von (Cl3PNPPh3)2[PCl6][ClHCl],[SbCl4(HNPPh3)2][SbCl6] und [Sb(NPPh3)4][SbCl6

AbstractOxidative Addition of N‐chlorotriphenylphosphoraneimine onto Phosphorus(III) Chloride and Antimony(III) Chloride. Crystal Structures of (Cl3PNPPh3)2[PCl6][ClHCl], [SbCl4(HNPPh3)2][SbCl6], and [Sb(NPPh3)4][SbCl6]Phosphorus(III) chloride reacts with N‐chlorotriphenylphosphoraneimine, ClNPPh3, in CH2Cl2 solution strongly exothermically via oxidative addition to give (Cl3PNPPh3)2[PCl6][ClHCl] (1). As a by‐product, Ph3PNP(O)Cl2 can be obtained, which is formed from PCl3 and ClNPPh3 in the presence of POCl3. In contrast to these results, antimony(III) chloride reacts with ClNPPh3 in CH2Cl2 solution to give a mixture of the phosphoraneimine complex [SbCl4(HNPPh3)2][SbCl6] (2) and the phosphoraneiminato complex [Sb(NPPh3)4][SbCl6] (3). The complexes 1‐3 were characterized by IR spectroscopy and by single crystal X‐ray determinations.1: Space group C2/c, Z = 4, lattice dimensions at 193 K: a = 3282.0(2), b = 798.7(1), c = 1926.1(2) pm, β = 107.96(1)°, R1 = 0.0302. 1 contains [Cl3PNPPh3]+ cations with PN bond lengths of 152.5(2) and 160.9(2) pm, and a PNP bond angle of 140.5(1)°.2·CH2Cl2: Space group ${\rm P}{\bar 1}$, Z = 2, lattice dimensions at 193 K: a = 1031.2(1), b = 1448.3(2), c = 1811,4(2) pm, α = 70.96(1)°, β = 87.67(1)°, γ = 75.37(1)°, R1 = 0.0713. 2·CH2Cl2 contains cations [SbCl4(HNPPh3)2]+ with octahedrally coordinated Sb atom and the HNPPh3 ligand molecules being in trans‐position. Sb–N bond lengths are 207.6(6) and 209.3(6) pm, PN bond lengths 162.3(7) and 160.8(7), which approximately corresponds with double bonds.3·0.5CH2Cl2: Space group P4/n, Z = 2, lattice dimensions at 193 K: a = b = 1678.8(1), c = 1244.3(1) pm, R1 = 0.0618. 3·0.5CH2Cl2 contains [Sb(NPPh3)4]+ cations with tetrahedrally coordinated Sb atom and short Sb–N bond lengths of 193.7(6) pm. The PN distances of the phosphoraneiminato ligands, (NPPh3)− with 156.5(6) pm, correspond with double bonds, the SbNP bond angles are 130.6(3)°.

Rhenium(V) and Technetium(V) Complexes with Phosphoraneimine and Phosphoraneiminato Ligands

Air-stable rhenium(V) nitrido complexes are formed when [ReOCl3(PPh3)2], [NBu4][ReOCl4], or [NBu4][ReNCl4] are treated with an excess of silylated phosphoraneiminates of the composition Me3SiNPPh3 or Ph2P(NSiMe3)CH2PPh2 in CH2Cl2. Complexes of the compositions [ReNCl(Ph2PCH2PPh2NH)2]Cl (1), [ReN(OSiMe3)(Ph2PCH2PPh2NH)2]Cl (2) or [ReNCl2(PPh3)2] (3) were isolated and structurally characterized. The latter compound was also produced during a reaction of the rhenium(III) precursor [ReCl3(PPh3)2(CH3CN)] and Me3SiNPPh3. Nitrogen transfer from the phosphorus to the rhenium atoms and the formation of nitrido ligands were observed in all examples. All products of reactions with an excess of the potentially chelating phosphoraneiminate Me3SiNP(Ph2)CH2PPh2 contain neutral Ph2PCH2PPh2NH ligands. The required protons are supplied by a metal-induced decomposition of the solvent dichloromethane. The Re-N(imine) bond lengths (2.055-2.110 A) indicate single bonds, whereas the N-P bond with lengths between 1.596 A and 1.611 A reflect considerable double bond character. An oxorhenium(V) phosphoraneiminato complex, the dimeric compound [ReOCl2(mu-N-Ph2PCH2PPh2N)]2 (4), is formed during the reaction of [NBu4][ReOCl4] with an equivalent amount of Ph2P(NSiMe3)CH2PPh in dry acetonitrile. The blue neutral complex with two bridging phosphoraneiminato units is stable as a solid and in dry solvents. It decomposes in solution, when traces of water are present. The rhenium-nitrogen distances of 2.028(3) and 2.082(3) A are in the typical range of bridging phosphoraneiminates and an almost symmetric bonding mode. Technetium complexes with phosphoraneimine ligands were isolated from reactions of [NBu4][TcOCl4] with Me3SiNPPh3, and [NBu4][TcNCl4] with Me3SiNP(Ph2)CH2PPh2. Nitrogen transfer and the formation of a five-coordinate nitrido species, [TcNCl2(HNPPh3)2] (5), was observed in the case of the oxo precursor, whereas reduction of the technetium(VI) starting material and the formation of the neutral technetium(V) complex [TcNCl2(Ph2PCH2PPh2NH)] (6) or [TcNCl(Ph2PCH2PPh2NH)2]Cl (7) was observed in the latter case. Both technetium complexes are air stable and X-ray structure determinations show bonding modes of the phosphoraneimines similar to those in the rhenium complexes.

Triphenylphosphinimino‐triphenylstiboniumchlorid, [Ph3PNSbPh3Cl], und seine Reaktion mit FeCl3

Abstract[Ph3PNSbPh3Cl] (1) was prepared by oxidative addition of ClNPPh3 to triphenylstibine in dichloromethane solution. The compound is characterized by IR spectroscopy and by an X‐ray structure determination. 1 crystallizes in the monoclinic space group P21/c with four formula units per unit cell. Lattice dimensions at 193 K: a = 925.3(1), b = 1777.2(1), c = 1825.5(1) pm, β = 94.07(1)°, R1 = 0.0228. 1 forms monomeric molecules with tetrahedrally coordinated phosphorus and trigonal‐bipyramidally coordinated antimony atom, the atoms N and Cl being in axial positions. The bond lengths PN and SbN are 155.0(2) and 198.4(2) pm, respectively, the PNSb angle is 138.6(1)°. 1 reacts with iron trichloride to give the known phosphoraneiminato complex [FeCl2(NPPh3)]2.

MNE Nitrido Bridges with Transition Metal Nitrogen Multiple Bonds and E = Phosphorus, Sulfur, and Chlorine

AbstractA compilation is given on new syntheses, properties, and structures of complexes with M≡N—E ↔ M=N=E nitrido bridges with transition metal nitrogen multiple bonds and participation of the main group elements E of phosporus, sulfur, and chlorine.1. MNP: This atomic sequence is realized in phosphoraneiminato complexes with transition metals in high oxidation states and termal bond of the (NPR3—) ligand. A series of new complexes of this type is reported with M = zirconium, hafnium, molybdenum, tungsten, and rhenium, among these the homoleptic species [Hf(NPPh3)4] and [M(NPPh3)4]2+ with M = Mo and W. Therefrom the isolobal complexes [:N≡Mo(NPPh3)3], [:O≡W(NPPh3)3]+, [(O)2Mo(NPPh3)2], and [(O)3Re(NPPh3)] are derived.2. MNS: Adding to compounds with this atomic sequence, new complexes were developed on the basis of the functional ligand groups thionitrosyl (a), dinitridosulphate(II) (b), dinitridosulphate(IV) (c), and cyclothiazeno (d) (cyclo‐3, 5‐dithia‐2, 4, 6‐triazino):magnified image3. MNCl: Novel N‐chloroimido complexes of tungsten are described. [F4W≡N—Cl]4, which is tetrameric according to the IR spectrum, was obtained by direct fluorination from [Cl4W≡N—Cl]2 or, surprisingly, from W(N)Cl3. With acetonitrile the monomeric molecular complex [CH3CN→WF4(≡N—Cl)] is formed. In an unexpected pathway K[F5W≡N—Cl] was obtained from a redox reaction of W(N)Cl3 with trimethylstannyl fluoride in the presence of potassium fluoride. The ionic compound forms double layers with short Cl···F contacts.

Synthesis, Crystal Structure, and Spectroscopic Characterization of the Phosphorane Iminato Complexes [Cl2BNPCl2NPCl3]2 and [Br2BNPCl3]2.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Molecular weight control and end group functionalization of polynorbornene by Ni(II)-initiated polymerization of norbornene in the presence of ethylene and ɑ-olefins

AbstractHigh-molecular-weight vinyl-type polynorbornene (PN) was obtained in high yields by a highly active nickel-based phosphorane iminato complex in the presence of methylaluminoxane. Termination of norbornene polymerization by functionalized ɑ-olefins yielded soluble end group functionalized polynorbornenes of controlled molecular weight. The impact of the ɑ-olefins on yield and Mn depends significantly on the sterical situation at the olefins. No proof for the incorporation of the olefin at any other position than the chain end was observed. Considerations based on yields and Mn suggest that the Ni hydride species, which is most likely formed upon β-H elimination reaction in the scheme of olefin addition to the growing PN chain, initiates a new PN chain; in other words, chain transfer occurs through β-H elimination reaction.

Ring-Opening Polymerization ofɛ-Caprolactone by Phosphorane Iminato and Cyclopentadienyl Complexes of Rare Earth Elements

Rare earth element complexes with triphenyl phosphorane iminato ligands such as [La 2 (NPPh 3 ) 4 (μ-NPPh 3 ) 2 (μ-THF)] and [Yb(NPPh 3 ) 3 ] 2 initiate the polymerization of e-caprolactone to give high molecular weight poly(e-caprolactone) with moderate polydispersity. The reactivity of these complexes is higher as compared to complexes with three cyclopentadienyl ligands with corresponding metal centers. The initiation mechanism for the polymerization of e-caprolactone by [La 2 (NPPh 3 ) 4 (μ-NPPh 3 ) 2 (μ-THF)] is discussed based on the end groups of low molecular weight polycaprolactones. Living chain ends of poly(e-caprolactone) were proved by block copolymerization of e-caprolactone and δ-valerolactone. The mixed complex [Cp 3 Dy 2 (NPPh 3 ) 3 ] has been successfully applied for ROP of CL. A significant increase in molecular weight of ROP has been observed with decrease of reaction temperature.

ChemInform Abstract: Synthesis and Reactivity of Perhalogenated Acyclic and Metallacyclic Tantalum(V) Phosphoraniminato Complexes: Discovery of an Unexpected Ligand Coupling Reaction to Form the Novel Phosphazenium Salt [N(PCl2NH2)2][TaCl6

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and reactivity of perhalogenated acyclic and metallacyclic tantalum(V) phosphoraniminato complexes: discovery of an unexpected ligand coupling reaction to form the novel phosphazenium salt.

The reaction of TaCl5 with a single equivalent of Cl3P=NSiMe3 resulted in the isolation of the perhalogenated (phosphoraniminato) tantalum(V) complex TaCl4(N=PCl3) (1). Reaction of 1 with an excess of THF and subsequent cooling produced crystals of TaCl4(N=PCl3)(THF) (1.THF), which possesses a distorted octahedral Ta center with a THF molecule coordinated trans to the phosphoraniminato ligand. The reaction of 1 with the aminophosphoranimine, (Me3Si)2NPCl2=NSiMe3, resulted in a [3 + 1] cyclocondensation reaction to form the metallacyclic complex, TaCl3(N=PCl3)[N(SiMe3)PCl2N(SiMe3)] (2), which contains a TaNPN four-membered ring and a phosphoraniminato ligand (N=PCl3). The analogous [3 + 1] cyclocondensation reaction between (Me3Si)2NPCl2=NSiMe3 and TaCl5 led to the isolation of TaCl4[N(SiMe3)PCl2N(SiMe3)] (3). An attempt to cleave the NPN ligand from the Ta center in 2 via protonolysis with HCl led to an unusual phosphoraniminato ligand coupling reaction to yield the novel phosphazenium salt [N(PCl2NH2)2][TaCl6] (4). All new compounds (1.THF and complexes 1-4) were characterized by single-crystal X-ray diffraction.

Cs[Yb(NPPh3)4] – ein homoleptischer Phosphaniminato-Komplex des Ytterbiums

Cs[Yb(NPPh3)4] – a Homoleptic Phosphoraneiminato Complex of Ytterbium Cesium tetrakis(phosphoraneiminato)ytterbate, Cs[Yb(NPPh3)4] (1) has been prepared by the reaction of the dimeric complex [Yb(NPPh3)3]2 with CsNPPh3 in thf solution. 1 crystallizes from thf solution to give colourless moisture sensitive crystals which contain three molecules thf per asymmetric unit. According to the crystal structure determination 1 forms a dimeric ion ensemble [Cs{Yb(NPPh3)4}]2 in which the Cs+ ions connect the [Yb(NPPh3)4]– ions via Cs…N bridges. The ytterbium atoms are distorted tetrahedrally coordinated by the nitrogen atoms of the phosphoraneiminato ligands (NPPh3–) with short Yb–N-bond lengths between 212.1 and 221.9(8) pm. The included thf molecules are without bonding contacts with the complex. [Cs{Yb(NPPh3)4}]2 · 6 thf: Space group P 1, Z = 2, lattice dimensions at 193 K: a = 1837.2(2), b = 2041.5(2), c = 2095.8(2) pm, α = 79.953(13)°, β = 79.364(11)°, γ = 88.239(12)°, R = 0.0625.

Kristallstruktur des Isothiocyanato-Komplexes [Ph3PNH2(OEt2)][Sm(NCS)4(DME)2

Crystal Structure of the Isothiocyanato Complex [Ph3PNH2(OEt2)][Sm(NCS)4(DME)2] Colourless single crystals of [Ph3PNH2(OEt2)][Sm(NCS)4(DME)2] (1) have been obtained besides of Ph3PS from the reaction of the homoleptic phosphorane iminato complex [Sm(NPPh3)3]2 with carbon disulfide in THF solution, followed by recrystallisation from DME/Et2O. According to the crystal structure analysis 1 consists of [Ph3PNH2]+ cations with the diethylether molecule forming a N–H…O hydrogen bridge, and anions [Sm(NCS)4(DME)2]–. Sm3+ realizes coordination number eight by four nitrogen atoms of the isothiocyanato ions and by four oxygen atoms of the DME chelates. 1: Space group P 1, Z = 4, lattice dimensions at 193 K: a = 919.0(1), b = 1965.2(2), c = 2401.3(2) pm, α = 96.748(11)°, β = 94.827(10)°, γ = 91.720(11)°, R = 0.029.

Homoleptic Phosphoraneiminato Complexes of Rare Earth Elements as Initiators for Ring-Opening Polymerization of Lactones.

Homoleptic Phosphoraneiminato Complexes of Rare Earth Elements as Initiators for Ring-Opening Polymerization of Lactones.

Phosphorane−Iminato Complexes of Transition Metals with Heterocubane Structure: A Computational Study

The electronic structure of phosphorane-iminato complexes of transition metals is studied by means of ab initio/DFT methods. Accordingly, the transition metal nitrogen bond is best described as an ionic interaction between a transition metal complex fragment and the strongly polarized NPH3- ligand. By elaborate MCSCF calculations a weak antiferromagnetic coupling of the four transition metal centers in the cubane core is predicted. This coupling can be represented by a simple Heisenberg Hamiltonian.

Osmium(VI) Nitrido and Osmium(IV) Phosphoraniminato Complexes Containing Schiff Base Ligands

A series of osmium(VI) nitrido complexes containing Schiff base ligands, [Os(VI)(N)(L)Cl] (L = salophen or salen), have been synthesized by reaction of the ligand with [NBu(n)(4)][Os(VI)(N)Cl(4)] in the presence of 2,6-dimethylpyridine. The nu(Os&tbd1;N) for the salophen complexes occur at around 1070 cm(-)(1) and are insensitive to the nature of the substituents present on the Schiff base ligand. The structures of [Os(N)(salophen)(MeOH)]ClO(4) and [Os(N)(5,5-Cl(2)salophen)(MeOH)]ClO(4) have been determined by X-ray crystallography, and the Os&tbd1;N bond distances are 1.651 and 1.66 Å, respectively. The osmium(VI) nitrido complexes react rapidly with triphenylphosphine to produce the corresponding osmium(IV) phosphoraniminato complexes, [Os(IV)(NPPh(3))(L)Cl]. The osmium(IV) complexes exhibit reversible Os(V/IV) and Os(IV/III) couples in cyclic voltammetry. The E(1/2) values show linear correlations with the Hammett constants sigma(p) of the substituents on the Schiff base ligand. The structure of [Os(IV)(NPPh(3))(salophen)Cl] has been determined by X-ray crystallography. The rather long Os-N(P) bond length (1.92 Å) and acute Os-N-P bond angle (149.6 degrees ) suggest that there is no significant multiple-bond character in the Os-N bond. The kinetics of nitrogen atom transfer from a series of 5,5'-disubstituted salophen nitrido complexes to PPh(3) have been studied in CH(3)CN at 25.0 degrees C by stopped-flow spectrophotometric method. The following rate law was obtained: -d[Os(VI)]/dt = k(2)[Os(VI)][PPh(3)]. The reactivities of the complexes were found to follow a Hammett correlation of log(k(X)/k(H)) with sigma(p), with a rho value of 1.9 +/- 0.1. The positive rho value is consistent with a transition state involving electrophilic attack by the nitrido ligand on the phosphorus atom.

Phosphoraneiminato Complexes of Manganese and Cobalt with Heterocubane Structure

The phosphoraneiminato complexes [MnBr(NPEt3)]4 (1) and [M4Br5{NP(NMe2)3}3] with M = Mn (2) and M = Co (3) are prepared by melting reactions from the anhydrous metal dibromides with the silylated phosphaneimines Me3SiNPR3 (R = Et, NMe2) in the presence of potassium fluoride. All complexes are characterized by crystal structure analyses. 1 forms an only slightly distorted Mn4N4 heterocubane skeleton with an approximate Td symmetry and short Mn…Mn distances of average 295.7 pm. In the structures of 2 and 3 one μ3-NPEt3 ligand of 1 is replaced by one bromine atom with μ3-function. This leads to the novel heterocubane type M4N3Br with approximate C3 symmetry. The deformation of the cubic skeleton leads to metal-metal distances of different lengths, i. e. 292.7 and 323.6 pm in 2 and 274.4 and 306.2 pm in 3. Temperature dependent magnetic susceptibility measurements between 300 and 5 K on 1 have shown that strong antiferromagnetic coupling exists between the Mn(II) ions with S = 5/2, with a large negative Weiss constant of Θ = –694 K. Phosphaniminato-Komplexe von Mangan und Cobalt mit Heterocubanstruktur Die Phosphaniminato-Komplexe [MnBr(NPEt3)]4 (1) und [M4Br5{NP(NMe2)3}3] mit M = Mn (2) und M = Co (3) werden durch Schmelzreaktionen aus den wasserfreien Metalldibromiden mit den silylierten Phosphaniminen Me3SiNPR3 (R = Et, NMe2) in Gegenwart von Kaliumfluorid hergestellt und durch Kristallstrukturanalysen charakterisiert. 1 bildet ein nur wenig verzerrtes Mn4N4-Heterocubangerüst mit angenäherter Td-Symmetrie und kurzen Mn…Mn-Abständen von im Mittel 295.7 pm. In den Strukturen von 2 und 3 ist ein μ3-NPEt3-Ligand von 1 durch ein Bromatom mit μ3-Funktion ersetzt, was zu dem neuen Heterocuban-Typ M4N3Br mit angenäherter C3-Symmetrie führt. Die Deformation des Würfelgerüstes führt zu verschieden langen Metall-Metall-Abständen in 2 von 292.7 und 323.6 pm, in 3 von 274.4 und 306.2 pm. Temperaturabhängige magnetische Suszeptibilitätsmessungen im Bereich 300 bis 5 K haben ergeben, daß die Mn(II)-Ionen mit S = 5/2 stark antiferromagnetisch untereinander gekoppelt sind; die Weisssche Konstante beträgt Θ = –694 K.

Vinyl-type polymerization of norbornene by a nickel-based catalyst with phosphoraneiminato ligands

High molecular weight vinyl-type polynorbornene was obtained in high yields with a highly active nickel-based phosphoraneiminato complex in the presence of methylaluminoxane. This polynorbornene is soluble at room temperature in chlorobenzene and shows no indication of crystallinity in the solid state. Catalyst activity, polymer yield, and polymer molecular weight can be controlled over a wide range by variation of reaction parameters.

Cu12(NPEt3)8]4+ and [Ag12(NPEt3)8]4+: Cubane Structures

Unusual, highly symmetrical cubes are formed by the dodecameric cationic phosphoraneiminato complexes of copper(I) and silver(I) [M12 (NPEt3 )8 ]4+ , in which the metal atoms occupy the edges and the N atoms of NPEt 3-3 groups the corners of the cube (see figure). The structures can be understood as molecular sections of the Cu3 N structure, which is inverse to the ReO3 -type structure.