Tetrahedral Phosphorus Research Articles

Triclinic La7Zn2P11 with P3-, P24-, and P35- units: a combined study by 31P solid-state NMR spectroscopy and single crystal X-ray diffraction.

The ternary polyphosphide La7Zn2P11 was synthesized from the elements by using a salt flux or via a ceramic method in sealed quartz ampoules. The obtained samples were investigated by X-ray powder and single crystal diffraction: own type, P1̄, a = 775.33(13), b = 827.45(13), c = 1502.8(3) pm, α = 82.111(3), β = 77.034(3), γ = 89.996(3)°, wR2 = 0.1553, 5852 F2 values and 183 variables. This peculiar structure is characterized by the simultaneous presence of three distinct anionic phosphide species, namely P3-, P24-, and P35- units. La7Zn2P11 is an electron precise Zintl phase: (7La3+)21+(2Zn2+)4+(4P3-)12-(2P24-)8-(P35-). The P-P single bond distances range from 219.2 to 223.0 pm. The zinc sites show tetrahedral phosphorus coordination by three P3- and one P24- species. The tetrahedra are condensed to chains via common corners. The P35- units with P-P-P angles of 113.7° have exclusively lanthanum coordination. 31P solid-state NMR was used to probe the phosphorus local environments, connectivities and spatial proximities. The eleven crystallographically distinct phosphorus atoms were assigned with the help of two-dimensional homonuclear dipolar correlation experiments. Even though the application of 2D measurements on such phosphorus-based polyanionic compounds is exceedingly challenging because of the wide dispersion of chemical shifts, the fast irreversible decay of the transverse magnetization, and slow spin-lattice relaxation, a complete assignment is possible using radiofrequency-driven dipolar recoupling (RFDR), J-RESOLVED and total-through-bond correlation with R-sequence (R-TOBSY) techniques.

Detection of 1H-Triphosphirene (c-HP3) and 2-Triphosphenylidene (HP3): The Isovalent Counterparts of 1H-Triazirine (c-HN3) and Hydrazoic Acid (HN3).

The hitherto elusive 1H-triphosphirene (c-HP3) and 2-triphosphenylidene (HP3) molecules were prepared in low-temperature matrices and detected isomer selectively through photoionization coupled with reflectron time-of-flight mass spectrometry (PI-ReTOF-MS). Our results reveal a thermodynamically preferred cyclic isomer (c-HP3) compared to the acyclic structure (HP3) in contrast to the isovalent HN3 system favoring hydrazoic acid (HN3) compared to 1H-triazirine (c-HN3). Theoretical computations suggest a ring strain energy of 1H-triphosphirene (c-HP3) of only 35 kJ mol-1, which is significantly lower than the tetrahedral phosphorus molecule (P4) of 74 kJ mol-1. This work provides a fundamental benchmark to understand the electronic structure and chemical bonding of cyclic molecules and offers an unconventional approach to preparing highly strained, still elusive molecules such as 1H-triazirine and tetrahedral tetranitrogen (N4) in the near future involving progressive nonequilibrium chemistries.

Configurational Lability at Tetrahedral Phosphorus: syn/anti‐Isomerization of a P‐Stereogenic Phosphiranium Cation by Intramolecular Epimerization at Phosphorus

AbstractTetrahedral main‐group compounds are normally configurationally stable, but P‐epimerization of the chiral phosphiranium cations syn‐ or anti‐[Mes*P(Me)CH2CHPh][OTf] (Mes*=2,4,6‐(t‐Bu)3C6H2) occurred under mild conditions at 60 °C in CD2Cl2, resulting in isomerization to give a syn‐enriched equilibrium mixture. Ion exchange with excess [NBu4][Δ‐TRISPHAT] (Δ‐TRISPHAT=Δ‐P(o‐C6Cl4O2)3) followed by chromatography on silica removed [NBu4][OTf] and gave mixtures of syn‐ and anti‐[Mes*P(Me)CH2CHPh][Δ‐TRISPHAT]⋅x[NBu4][Δ‐TRISPHAT]. NMR spectroscopy showed that isomerization proceeded with epimerization at P and retention at C. DFT calculations are consistent with a mechanism involving P‐C cleavage to yield a hyperconjugation‐stabilized carbocation, pyramidal inversion promoted by σ‐interaction of the P lone pair with the neighboring β‐carbocation, and ring closure with inversion of configuration at P.

Configurational Lability at Tetrahedral Phosphorus: syn/anti-Isomerization of a P-Stereogenic Phosphiranium Cation by Intramolecular Epimerization at Phosphorus.

Tetrahedral main-group compounds are normally configurationally stable, but P-epimerization of the chiral phosphiranium cations syn- or anti-[Mes*P(Me)CH2 CHPh][OTf] (Mes*=2,4,6-(t-Bu)3 C6 H2 ) occurred under mild conditions at 60 °C in CD2 Cl2 , resulting in isomerization to give a syn-enriched equilibrium mixture. Ion exchange with excess [NBu4 ][Δ-TRISPHAT] (Δ-TRISPHAT=Δ-P(o-C6 Cl4 O2 )3 ) followed by chromatography on silica removed [NBu4 ][OTf] and gave mixtures of syn- and anti-[Mes*P(Me)CH2 CHPh][Δ-TRISPHAT]⋅x[NBu4 ][Δ-TRISPHAT]. NMR spectroscopy showed that isomerization proceeded with epimerization at P and retention at C. DFT calculations are consistent with a mechanism involving P-C cleavage to yield a hyperconjugation-stabilized carbocation, pyramidal inversion promoted by σ-interaction of the P lone pair with the neighboring β-carbocation, and ring closure with inversion of configuration at P.

Structural Insights into Catalytic Relevances of Substrate Poses in ACC-1.

ACC-1 is a plasmid-encoded class C β-lactamase identified in clinical isolates of Klebsiella pneumoniae, Proteus mirabilis, Salmonella enterica, and Escherichia coli ACC-1-producing bacteria are susceptible to cefoxitin, whereas they are resistant to oxyimino cephalosporins. Here, we depict crystal structures of apo ACC-1, adenylylated ACC-1, and acylated ACC-1 complexed with cefotaxime and cefoxitin. ACC-1 has noteworthy structural alterations in the R2 loop, the Ω loop, and the Phe119 loop located along the active-site rim. The adenylate covalently bonded to the nucleophilic serine reveals a tetrahedral phosphorus mimicking the deacylation transition state. Cefotaxime in ACC-1 has a proper conformation for the substrate-assisted catalysis in that its C-4 carboxylate and N-5 nitrogen are adequately located to facilitate the deacylation reaction. In contrast, cefoxitin in ACC-1 has a distinct conformation, in which those functional groups cannot contribute to catalysis. Furthermore, the orientation of the deacylating water relative to the acyl carbonyl group in ACC-1 is unfavorable for nucleophilic attack.

Two symmetric arginine residues play distinct roles in Thermus thermophilus Argonaute DNA guide strand-mediated DNA target cleavage

Bacterium Thermus thermophilus Argonaute (Ago; TtAgo) is a prokaryotic Ago (pAgo) that acts as the host defense against the uptake and propagation of foreign DNA by catalyzing the DNA cleavage reaction. The TtAgo active site consists of a plugged-in glutamate finger with two arginine residues (R545 and R486) located symmetrically around it. An interesting challenge is to understand how they can collaboratively facilitate enzymatic catalysis. In Kluyveromyces polysporus Ago, a eukaryotic Ago, the evolutionarily symmetrical residues are arginine and histidine, both of which function to stabilize the plugged-in catalytic tetrad conformation. Surprisingly, our simulation results indicated that, in TtAgo, only R545 is involved in the cleavage reaction by serving as a critical structural anchor to stabilize the catalytic tetrad Asp-Glu-Asp-Asp that is completed by the insertion of the glutamate finger, whereas R486 is not involved in target cleavage. The TtAgo-mediated target DNA cleavage occurs in a substrate-assisted mechanism, in which the pro-Rp (Rp, a tetrahedral phosphorus center with "R-type" chirality) oxygen of scissile phosphate acts as a general base to activate the nucleophilic water. Our unexpected theoretical findings on distinct roles played by R545 and R486 in TtAgo catalysis have been validated by single-point site-mutagenesis experiments, wherein the target cleavage is abolished for all mutants of R545. In sharp contrast, the cleavage activity is maintained for all mutants of R486. Our work provides mechanistic insights on the catalytic specificity of Ago proteins and could facilitate the design of new gene-editing tools in the long term.

Phosphasalen vs. Salen Ligands: What Does the Phosphorus Change?

Phosphasalen ligands can be viewed as the phosphorus analogues of salen, in which the imine functions were replaced by iminophosphoranes (P=N). Their divergent stereoelectronic properties compared to salen, namely larger electron‐donation, higher flexibility, and larger steric hindrance due to the presence of two substituents on the tetrahedral phosphorus atoms, were exploited in coordination chemistry and catalysis. They were proven to be able to stabilize metals in unusual oxidation states; square planar copper(III) and nickel(III) complexes were isolated. Because of the redox non‐innocent character of these ligands, the electronic structure of the one‐electron oxidized complexes was studied in depth to determine the metallic vs. ligand contribution in the overall delocalization. In addition, the catalytic activity of different phosphasalen complexes was proven for the ring opening polymerization of lactide, and rare‐earth phosphasalen complexes were shown to be powerful, rapid, controlled, and stereoselective initiators. Importantly, the stereochemical outcome of the reaction can be tuned by changing the ligand structure or the metal. In particular, efficient iso‐selective initiators were developed.

Synthesis of Phosphinopeptides via the Mannich Ligation

Phosphinopeptides are a class of unnatural peptides containing a tetrahedral phosphorus atom and have potential for use as enzyme inhibitors. A series of phosphinopeptides were synthesized via the Mannich-type reaction of aryldichlorophosphines, aldehydes, and N-protected amino amides or peptide amides and subsequent aminolysis with amino esters or peptide esters. The current method named the Mannich ligation is an efficient route to synthesis of phosphinopeptides through convergent condensation.

New Anions of Pentacoordinate Phosphorus Containing Fluorine and Trifluoromethyl Groups

AbstractThe unique pseudo‐trigonal‐bipyramidal CF3PF3O– and (CF3)2PF2O– anions were obtained and characterised for the first time. They were formed by the reactions of (PhO)3P(O), Me3SiCF3 and the fluoride ion sources [Me4N]F and CsF, respectively, in glyme. These anions represent the stable transition states postulated for nucleophilic substitution at a tetrahedral phosphorus atom. The salt Cs[(CF3)2PF2O] (7) is stable at room temperature for a month, while [Me4N][CF3PF3O] (1) dismutates into [Me4N][CF3PF(O)O] (2) and [Me4N][CF3PF5] (3) above 0 °C. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Structure of an aluminophosphate EMM-8: a multi-technique approach

The crystal structure of an aluminophosphate, EMM-8 (ExxonMobil Material #8), was determined in its calcined, anhydrous form from synchrotron powder diffraction data using the computer program FOCUS. A linkage of double four-ring (D4R) building units forms a two-dimensional framework with 12-MR and 8-MR channels, and differs from a similar SAPO-40 (AFR) framework only by the relationship between paired D4R units. Rietveld refinement reveals a fit of the model to the observed synchrotron data by Rwp=0.1118, R(F2)=0.1769. Local environments of the tetrahedral phosphorus and aluminium sites were established by solid-state NMR, which detects distinct differences between as-synthesized and calcined materials. Distinct, reversible changes in the local symmetry of the P and Al atoms were observed by NMR upon calcination and subsequent hydration. These NMR data provided important constraints on the number of tetrahedral (T) atoms per unit cell and the connectivities of the T atoms. Detailed local structural information obtained by solid-state NMR thereby guided the ultimate determination of the structure of AlPO EMM-8 from the powder data. Comparisons are made to the recently published crystal structure of the fluoride-containing, as-synthesized SSZ-51, indicating that the unit-cell symmetry, axial dimensions and framework structure are preserved after calcination.

Isomorphous Substitution of Transition-Metal Ions in the Nanoporous Nickel Phosphate VSB-5

The transition-metal-incorporated nickel phosphate molecular sieves (TMI-VSB-5) have been hydrothermally synthesized at 453 K in weak basic conditions under microwave irradiation. By means of X-ray diffraction, inductively coupled plasma (ICP), ultraviolet-visible (UV-vis) diffuse reflectance, and Mössbauer spectroscopies, successful isomorphous (at least partial) substitution of transition-metal ions in the VSB-5 framework has been verified. Characterization results show that the framework structure of nanoporous VSB-5 can accommodate a substantial level of isomorphous substitution of transition-metal ions up to about 10, 5, and 3 atom % for Fe, Mn, and V, respectively, in both octahedral nickel sites (Mn and Fe) and tetrahedral phosphorus sites (V). The isomorphous substitution including the replacement mechanism was studied by not only the change of unit cell parameters but also spectroscopic analysis. The unit cell parameters of TMI-VSB-5 including a unit cell volume and a-axis length relied on the ionic radii difference between the incorporated ion and the original framework ions such as Ni or P (RTMI - RNi or RTMI - RP).

Trans-2-(Dimethoxyphosphinoyl)-1-phenyl-1-(1,1,3,3-tetramethyl-2,3-dihydro-1H-isoindol-2-yloxy)ethene

The structure of the compound CHNOP was investigated. The central feature of the compound is a tetrahedral phosphorus atom attached to two methoxy groups, a phosphate oxygen and an isoindoloxy group. There is a possible C2-H2···N5 intramolecular hydrogen bond and an intermolecular link. The compound is important for the study of the reaction of phosphorus-centered radicals with alkenes and alkynes.

Phase formation and evolution in the silicon substituted tricalcium phosphate/apatite system

The sintering of silicon doped calcium phosphate ceramics prepared from a basic colloidal hydroxyapatite (Ca 5(PO 4) 3OH or HA) precipitate mixed with silica over 800 °C yields a phase mixture of tricalcium phosphate phases (TCP) designated Si–TCP, β-TCP and a silicon substituted dehydrated apatite (Si–Ap). The Si–TCP phase is defined as a combination of a silicon stabilized TCP in which the silicon content attains a saturated value (Ca 3(P 0.9Si 0.1O 3.95) 2 or Si–TCP sat) and α-TCP (Ca 3(PO 4) 2). Si–TCP sat has the same crystalline space group (P2 1/a) as α-TCP, but with characteristically different lattice parameters due to the substitution of silicon in tetrahedral phosphorus sites. The nucleation and growth kinetics of Si–TCP in samples of composition 0.2 mol SiO 2:mol HA (0.2:1) and 1 mol SiO 2:mol HA (1:1) can be understood in terms of the initial growth of α-TCP at a silica-HA interface followed by a transformation to Si–TCP sat or β-TCP. A thermodynamic model for the formation of Si–TCP sat predicts a nucleation temperature of 795 °C, in close agreement with experiment. If sufficient silicon is available, the α-TCP transforms to Si–TCP sat during extended sintering. In the absence of sufficient silicon, the α-TCP transforms to β-TCP.

Mechanism of Inactivation of Ornithine Transcarbamoylase by Nδ-(N′-Sulfodiaminophosphinyl)-l-ornithine, a True Transition State Analogue?: CRYSTAL STRUCTURE AND IMPLICATIONS FOR CATALYTIC MECHANISM

The crystal structure is reported at 1.8 A resolution of Escherichia coli ornithine transcarbamoylase in complex with the active derivative of phaseolotoxin from Pseudomonas syringae pv. phaseolicola, N(delta)-(N'-sulfodiaminophosphinyl)-l-ornithine. Electron density reveals that the complex is not a covalent adduct as previously thought. Kinetic data confirm that N(delta)-(N'-sulfodiaminophosphinyl)-l-ornithine exhibits reversible inhibition with a half-life in the order of approximately 22 h and a dissociation constant of K(D) = 1.6 x 10(-12) m at 37 degrees C and pH 8.0. Observed hydrogen bonding about the chiral tetrahedral phosphorus of the inhibitor is consistent only with the presence of the R enantiomer. A strong interaction is also observed between Arg(57) Nepsilon and the P-N-S bridging nitrogen indicating that imino tautomers of N(delta)-(N'-sulfodiaminophosphinyl)-l-ornithine are present in the bound state. An imino tautomer of N(delta)-(N'-sulfodiaminophosphinyl)-l-ornithine is structurally analogous to the proposed reaction transition state. Hence, we propose that N(delta)-(N'-sulfodiaminophosphinyl)-l-ornithine, with its three unique N-P bonds, represents a true transition state analogue for ornithine transcarbamoylases, consistent with the tight binding kinetics observed.

Mechanism of oxime reactivation of acetylcholinesterase analyzed by chirality and mutagenesis.

Organophosphates inactivate acetylcholinesterase by reacting covalently with the active center serine. We have examined the reactivation of a series of resolved enantiomeric methylphosphonate conjugates of acetylcholinesterase by two oximes, 2-pralidoxime (2-PAM) and 1-(2'-hydroxyiminomethyl-1'-pyridinium)-3-(4'-carbamoyl-1-pyridinium) (HI-6). The S(p) enantiomers of the methylphosphonate esters are far more reactive in forming the conjugate with the enzyme, and we find that rates of oxime reactivation also show an S(p) versus R(p) preference, suggesting that a similar orientation of the phosphonyl oxygen toward the oxyanion hole is required for both efficient inactivation and reactivation. A comparison of reactivation rates of (S(p))- and (R(p))-cycloheptyl, 3,3-dimethylbutyl, and isopropyl methylphosphonyl conjugates shows that steric hindrance by the alkoxy group precludes facile access of the oxime to the tetrahedral phosphorus. To facilitate access, we substituted smaller side chains in the acyl pocket of the active center and find that the Phe295Leu substitution enhances the HI-6-elicited reactivation rates of the S(p) conjugates up to 14-fold, whereas the Phe297Ile substitution preferentially enhances 2-PAM reactivation by as much as 125-fold. The fractional enhancement of reactivation achieved by these mutations of the acyl pocket is greatest for the conjugated phosphonates of the largest steric bulk. By contrast, little enhancement of the reactivation rate is seen with these mutants for the R(p) conjugates, where limitations on oxime access to the phosphonate and suboptimal positioning of the phosphonyl oxygen in the oxyanion hole may both slow reactivation. These findings suggest that impaction of the conjugated organophosphate within the constraints of the active center gorge is a major factor in influencing oxime access and reactivation rates. Moreover, the individual oximes differ in attacking orientation, leading to the presumed pentavalent transition state. Hence, their efficacies as reactivating agents depend on the steric bulk of the intervening groups surrounding the tetrahedral phosphorus.

35Cl NQR spectra, structure, and mutual influence of substituents in the series of chlorine-containing organic compounds of pentavalent phosphorus

Regularities of transmission of the effect of equatorial and axial substituents were established for a number of chlorine-containing organic compounds of pentatalent phosphorus using35Cl NQR spectra. The field constants of35Cl NQR frequencies of the chlorine atoms participating in the P−Cl bond were estimated for a series of tetrahedral phosphorus ions. The35Cl NQR frequencies of chlorine atoms in tetracoordinated ions of pentavalent phosphorus and in analogous isoelectronic silicon compounds are related by a linear dependence.

Electron Spin Resonance and Electron Spin−Echo Modulation Evidence for the Isomorphous Substitution of Titanium in Titanium Aluminophosphate Molecular Sieves

A series of titanium aluminophosphate molecular sieves with four different structure types including TAPO-5 (AFI topology), TAPO-11 (AEL topology), TAPO-31 (ATO topology), and TAPO-36 (ATS topology) have been studied to determine the titanium location in the aluminophosphate framework. Some Ti(IV) was reduced to paramagnetic Ti(III) by γ-irradiation and CO reduction to serve as a spin probe. The electron spin resonance (ESR) parameters confirm Ti(III) formation but do not clearly confirm a tetrahedral environment. However, 31P and 27Al electron spin−echo modulation of Ti(III) provide evidence based on phosphorus distances for titanium substitution into a tetrahedral phosphorus site of the aluminophosphate framework in all four structures. When the TAPOs are treated with NO, an NO radical is observed by ESR but Ti(III) is not formed.

Reaction of N-(Benzylkoxycarbonylamino) Benzylphosphonous Acid with Ethyl Orthoformate

Peptide containing phosphinic acids are peptidomimetics which have been successfidly employed m the design of inhibitors of protease and ligase enzymes. These stable tetrahedral phosphorus species act by mimicking the tetrahedral mtemediates of the reactions catalyzed by these two groups of enzymes. Using this concept potent transition-state analogue inhibitors of a wide variety of protenses, as well as of some tigases have been developed and studied m some detail. One of the key problems m the synthesis of these peptidomimetics is the conversion of readily available N-blocked 1 -aminoakylphosphonous acids or their esters mto corresponding phosphinic acids.

Characterization of Aluminophosphate-Based Tubular Mesoporous Molecular Sieves

A series of aluminophosphate-based tubular mesoporous molecular sieves without (UHM-1) and with substituted silicon (UHM-3) have been synthesized at room temperature in the presence of a cationic surfactant cetyltrimethylammonium chloride (CTACl) and an organic base tetramethylammonium hydroxide (TMAOH). Characterization by powder X-ray diffraction (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), N2 adsorption, and 27Al, 31P, and 29Si magic-angle-spinning (MAS) NMR spectroscopies has been carried out to understand both the pore structures and the local atomic arrangements of these solid products. The synthesis of UHM-1 and UHM-3 is successful only at room temperature within the following molar gel composition: Al2O3:(0.6−3.4) P2O5:(0.0−1.0) SiO2:(0.24−0.50) CTACl:(8.5−47.0) TMAOH:(200−642) H2O. The presence of TMAOH is essential to maintain the gel pH at 8.5 or above. The pH greatly influences the nature of the final “crystalline” products, particularly the coordination of aluminum and phosphorus. XRD, EPMA, TEM, and N2 adsorption measurements show that these solid products have a unique composition and disordered tubular mesopores with an average pore diameter of about 35 Å in the calcined form. The overall P/Al ratio of UHM-1 is less than unity, especially in gels of higher pH, indicating incomplete condensation of phosphorus and a nonideal aluminophosphate framework. This may account for their poorer thermal stability relative to microporous aluminophosphate molecular sieves and aluminosilicate-based MCM-41 materials. 27Al and 31P MAS NMR reveal that aluminum in UHM-1 with a P/Al ratio of 0.60 synthesized at a gel pH of 8.5 is present in both tetrahedral and octahedral environments while phosphorus is present in a tetrahedral environment and also as hydroxylated species. As the P/Al ratio of UHM-1 decreases together with increasing gel pH, the relative amounts of tetrahedral aluminum and tetrahedral phosphorus decrease. This change suggests some Al−O−P linkages in the tetrahedral regions of the UHM-1 samples, and an increasing octahedral aluminum content at lower P/Al ratio indicates that octahedral aluminum alone can construct a tubular mesoporous structure. After incorporation of silicon into UHM-1, 29Si, 27Al, and 31P MAS NMR of UHM-3 reveal that silicon is atomically dispersed and that the relative amounts of tetrahedral aluminum and tetrahedral phosphorus increase monotonically with increasing silicon incorporation. Virtually all the aluminum is tetrahedral, and all the phosphorus is tetrahedral after silicon incorporation reaches a Si/Al ratio of unity. This indicates more ordered atomic arrangements of tetrahedral silicon, aluminum, and phosphorus via oxygen bridges in UHM-3 than in UHM-1. The incorporation of silicon appears to make the aluminophosphate framework more flexible and facilitates the formation of an aluminophosphate-based mesoporous structure.

A 3-D Organically Templated Mixed Valence (Fe2+/Fe3+) Iron Phosphate with Oxide-Centered Fe4O(PO4)4 Cubes: Hydrothermal Synthesis, Crystal Structure, Magnetic Susceptibility, and Mössbauer Spectroscopy of [H3NCH2CH2NH3]2[Fe4O(PO4)4]·H2O

A 3-D, open framework, mixed valence iron phosphate, [H3NCH2CH2NH3]2[Fe4O(PO4)4]·H2O, which contains organic ethylenediammonium dications in the framework voids, has been prepared via hydrothermal synthesis and has been characterized by single-crystal X-ray diffraction, magnetic susceptibility, and variable temperature Mössbauer spectroscopy. Crystal data: tetragonal, space group I4̄2m with a = 10.1383(8) Å, c = 9.628(1) Å, V = 989.6(1) Å3, Z = 2, and R(Rw) = 7.7(6.5) for 276 reflections (I > 3σ(I)) and 32 variables. The fundamental building block of the structure is a novel cubane-like cluster with trigonal bipyramidal iron and tetrahedral phosphorus atoms lying at alternate vertexes of a cube with a tetrahedrally coordinated oxygen atom at the center of the cube. Each cluster is linked by eight Fe−O−P bonds that extend along what would be all 〈111〉 directions of the putative cube to eight similar clusters to form a framework that is only slightly distorted (by the presence of the organic cations) from cubic 4̄3m symmetry. Mössbauer and ac magnetic susceptibility measurements show that equal amounts of valence trapped Fe2+ and Fe3+ are present, which undergo long range magnetic ordering at ∼12 K.