Showing papers by "Alexander J. Blake published in 2013"
TL;DR: Computational analyses suggest covalent contributions to U≡N triple bonds that are surprisingly comparable to those of their group 6 transition-metal nitride counterparts.
Abstract: A terminal uranium(VI)–nitride has been shown to be accessible and isolable by a redox strategy whereas a photochemical approach resulted in decomposition. Computational analyses suggest that the U≡N triple bonds are surprisingly comparable to analogous group 6 transition metal nitrides, with a covalent character dominated by 5f rather than 6d contributions.
214 citations
TL;DR: In this paper, a C3-symmetric angularly connected isophthalate linker containing 1,2,3-triazole rings and shows body-centered tetragonal packing of cuboctahedra is used to achieve high H2, CH4 and CO2 adsorption capacities in desolvated NotT-122a.
Abstract: The highly porous (3,24)-connected framework NOTT-122 incorporates a C3-symmetric angularly connected isophthalate linker containing 1,2,3-triazole rings and shows body-centered tetragonal packing of [Cu24(isophthalate)24] cuboctahedra. This unique packing, coupled with the high density of free N-donor sites, is responsible for the simultaneous high H2, CH4 and CO2 adsorption capacities in desolvated NOTT-122a.
119 citations
TL;DR: Porous NOTT-202a shows exceptionally high uptake of SO2, 13.6 mmol g(-1) (87.0 wt %) at 268 K and 1.0 bar, representing the highest value reported to date for a framework material.
Abstract: Porous NOTT-202a shows exceptionally high uptake of SO2, 13.6 mmol g–1 (87.0 wt %) at 268 K and 1.0 bar, representing the highest value reported to date for a framework material. NOTT-202a undergoes a distinct irreversible framework phase transition upon SO2 uptake at 268–283 K to give NOTT-202b which has enhanced stability due to the formation of strong π···π interactions between interpenetrated networks.
116 citations
TL;DR: The first monometallic uranium(V), 5f SMM, is reported, where the physical properties result from imposing a strongly axial ligand field with C3v symmetry, the first unambiguous confirmation that uranium (V) complexes can indeed exhibit SMM behavior.
Abstract: Single-molecule magnets (SMMs) are defined as molecules that exhibit slow relaxation of magnetization of purely molecular origin. SMMs are intensively researched not only for their important fundamental physics, but also because of potential applications in high-density data storage, quantum information processing, and spintronics. These applications are conceivable because SMMs generally possess well-isolated high-spin ground states in which spin– orbit coupling results in zero-field splitting of the (2S + 1)fold degenerate ground multiplet. 6] This phenomenon creates a thermal barrier to the relaxation of the magnetization which gives rise to slow magnetic relaxation and magnetic bistability. Great advances have been made with lanthanide SMMs arising from the huge magnetic anisotropies that can result from the crystal field splitting of the total angular momentum (J) ground states. Very recently, there has been great interest in actinide and especially uranium SMMs. This stems from the same phenomena, but with the potential advantage that uranium can engage in covalent bonding which can enable stronger magnetic interactions. However, only a handful of uranium-based SMMs have been isolated, and the ground rules for maximizing their blocking temperatures are not clear. Furthermore, when we initiated this study all uranium SMMs exploited the highly anisotropic (5f) Kramers ion uranium(III) which has an I9/2 ground state. We reasoned that a highly anisotropic, strongly axially coordinated ligand environment at a uranium(V) Kramers ion should engender increased magnetic anisotropy and thus SMM behavior, despite the smaller total angular momentum (F5/2) of uranium(V) compared to uranium(III). Here we report the first monometallic uranium(V), 5f SMM, where the physical properties result from imposing a strongly axial ligand field with C3v symmetry. Recently, a uranyl(V)/manganese(II) (UO2)12Mn6 N,N’ethylenebis(salicylimine) cluster was demonstrated to exhibit SMM behavior. In this cluster the authors speculate that there is significant exchange coupling between the uranyl(V) and Mn ions, hence the relative importance of the ligand field and exchange coupling to the SMM behavior was unclear. We now report a triamidoamine uranium(V) terminal-oxo complex which is a SMM. This monometallic uranium(V) SMM provides the first unambiguous confirmation that uranium(V) complexes can indeed exhibit SMM behavior. We previously reported the trivalent uranium complex [U(Tren)] [1, Tren = {N(CH2CH2NSiiPr3)3} 3 ] and its use in the preparation of a terminal uranium(V)-nitride by a two-electron oxidation with sodium azide and the abstraction of the sodium ion with [12]crown-4 ether. Similarly, two-electron oxidation of 1 with trimethyl-N-oxide in toluene afforded the terminal mono-oxo uranium(V) complex [U(O)(Tren)] (2 ; Scheme 1 and Figure 1) as red crystals in 52% yield following work-up and recrystallization from hexane.
113 citations
TL;DR: Theoretical calculations have enabled a qualitative bracketing of the extent of covalency in early-metal carbenes as a function of metal, oxidation state and the number of phosphanyl substituents, revealing modest covalent contributions to U=C double bonds.
Abstract: Treatment of [K(BIPM(Mes)H)] (BIPM(Mes)={C(PPh2NMes)2}(2−); Mes=C6H2-2,4,6-Me3) with [UCl4(thf)3] (1 equiv) afforded [U(BIPM(Mes)H)(Cl)3(thf)] (1), which generated [U(BIPM(Mes))(Cl)2(thf)2] (2), following treatment with benzyl potassium. Attempts to oxidise 2 resulted in intractable mixtures, ligand scrambling to give [U(BIPM(Mes))2] or the formation of [U(BIPM(Mes)H)(O)2(Cl)(thf)] (3). The complex [U(BIPM(Dipp))(μ-Cl)4(Li)2(OEt2)(tmeda)] (4) (BIPM(Dipp)={C(PPh2NDipp)2}(2−); Dipp=C6H3-2,6-iPr2; tmeda=N,N,N′,N′-tetramethylethylenediamine) was prepared from [Li2(BIPM(Dipp))(tmeda)] and [UCl4(thf)3] and, following reflux in toluene, could be isolated as [U(BIPM(Dipp))(Cl)2(thf)2] (5). Treatment of 4 with iodine (0.5 equiv) afforded [U(BIPM(Dipp))(Cl)2(μ-Cl)2(Li)(thf)2] (6). Complex 6 resists oxidation, and treating 4 or 5 with N-oxides gives [{U(BIPM(Dipp)H)(O)2- (μ-Cl)2Li(tmeda)] (7) and [{U(BIPM(Dipp)H)(O)2(μ-Cl)}2] (8). Treatment of 4 with tBuOLi (3 equiv) and I2 (1 equiv) gives [U(BIPM(Dipp))(OtBu)3(I)] (9), which represents an exceptionally rare example of a crystallographically authenticated uranium(VI)–carbon σ bond. Although 9 appears sterically saturated, it decomposes over time to give [U(BIPM(Dipp))(OtBu)3]. Complex 4 reacts with PhCOtBu and Ph2CO to form [U(BIPM(Dipp))(μ-Cl)4(Li)2(tmeda)(OCPhtBu)] (10) and [U(BIPM(Dipp))(Cl)(μ-Cl)2(Li)(tmeda)(OCPh2)] (11). In contrast, complex 5 does not react with PhCOtBu and Ph2CO, which we attribute to steric blocking. However, complexes 5 and 6 react with PhCHO to afford (DippNPPh2)2C=C(H)Ph (12). Complex 9 does not react with PhCOtBu, Ph2CO or PhCHO; this is attributed to steric blocking. Theoretical calculations have enabled a qualitative bracketing of the extent of covalency in early-metal carbenes as a function of metal, oxidation state and the number of phosphanyl substituents, revealing modest covalent contributions to U=C double bonds.
85 citations
TL;DR: Straightforward access to a cerium(IV)-carbene complex was provided by one-electron oxidation of an anionic "ate" Cerium(III)- carbene precursor, thereby avoiding decomposition reactions that plague oxidations of neutral cerium (III) compounds.
Abstract: Straightforward access to a cerium(IV)-carbene complex was provided by one-electron oxidation of an anionic "ate" cerium(III)-carbene precursor, thereby avoiding decomposition reactions that plague oxidations of neutral cerium(III) compounds. The cerium(IV)-carbene complex is the first lanthanide(IV)-element multiple bond and involves a twofold bonding interaction of two electron pairs between cerium and carbon.
80 citations
TL;DR: Zintl clusters, exemplified by the heptaphosphanortricyclane trianion [P7]3−, are fundamentally interesting and important structural units in solid-state and molecular chemistry.
Abstract: Zintl clusters,[1] exemplified by the heptaphosphanortricyclane trianion [P7]3−, are fundamentally interesting and important structural units in solid-state and molecular chemistry.[1, 2] Their importance derives from the key role they have played in the development of polyhedral bonding models and isoelectronic relationships to cycloalkanes as well as synthetic applications.[3]–[5]
51 citations
TL;DR: It is reported that reductive [2+2]-cycloaddition reactions of diphenylacetylene and (2,2-dimethylpropylidyne)phosphine with uranium(V)-inverted sandwich 10π-toluene tetra-anion complexes results in the isolation of inverted sandwich cyclobutadienyl and diphosphacyclobutdienyl dianion uranium(IV) complexes.
Abstract: Despite the abundance of f-block-cyclopentadienyl, arene, cycloheptatrienyl and cyclo-octatetraenide complexes, cyclobutadienyl derivatives are unknown in spite of their prevalence in the d-block. Here we report that reductive [2+2]-cycloaddition reactions of diphenylacetylene and (2,2-dimethylpropylidyne)phosphine with uranium(V)-inverted sandwich 10π-toluene tetra-anion complexes results in the isolation of inverted sandwich cyclobutadienyl and diphosphacyclobutadienyl dianion uranium(IV) complexes. Computational analysis suggests that the bonding is predominantly electrostatic. Although the ψ4 molecular orbital in the cyclobutadienyl and diphosphacyclobutadienyl ligands exhibits the correct symmetry for δ-bonding to uranium, the dominant covalent contributions arise from π-bonding involving ψ2 and ψ3 orbital combinations. This contrasts with uranium complexes of larger arenes and cyclo-octatetraenide, where δ-bonding dominates. This suggests that the angular requirements for uranium to bond to a small four-membered ring favours π-bonding, utilizing 5f- instead of 6d-orbitals, over δ-bonding that is favoured with larger ligands, where 6d-orbitals can become involved in the bonding.
46 citations
TL;DR: Combined structural, spectroscopic, magnetic, and computational analyses unambiguously confirm that the uranium centres in 3 are in the +5 oxidation state and the toluene is a 10π-tetraanion.
Abstract: Reduction of [U(TsTol)(Cl)(μ-Cl)U(TsTol)(THF)2] [2, TsTol = HC(SiMe2NAr′)3; Ar′ = 4-MeC6H4)] with KC8 in toluene afforded the new arene-bridged diuranium complex [{U(TsTol)}2(μ–η6:η6-C6H5Me)] (3); combined structural, spectroscopic, magnetic, and computational analyses unambiguously confirm that the uranium centres in 3 are in the +5 oxidation state and the toluene is a 10π-tetraanion.
42 citations
TL;DR: Five-coordinate Zn(II, Ni(II), and Cu(II) complexes containing pentadentate N(3)O(2) Schiff base ligands have been synthesized and characterized and it is confirmed that each oxidation process is ligand-based with sequential formation of mono- and bis-phenoxyl radical species.
Abstract: Five-coordinate ZnII, NiII, and CuII complexes containing pentadentate N3O2 Schiff base ligands [1A]2– and [1B]2– have been synthesized and characterized. X-ray crystallographic studies reveal five coordinate structures in which each metal ion is bound by two imine N-donors, two phenolate O-donors, and a single amine N-donor. Electron paramagnetic resonance (EPR) spectroscopic studies suggest that the N3O2 coordination spheres of [Cu(1A)] and [Cu(1B)] are retained in CH2Cl2 solution and solid-state superconducting quantum interference device (SQUID) magnetometric studies confirm that [Ni(1A)] and [Ni(1B)] adopt high spin (S = 1) configurations. Each complex exhibits two reversible oxidation processes between +0.05 and +0.64 V vs [Fc]+/[Fc]. The products of one- and two-electron oxidations have been studied by UV/vis spectroelectrochemistry and by EPR spectroscopy which confirm that each oxidation process for the ZnII and CuII complexes is ligand-based with sequential formation of mono- and bis-phenoxyl ra...
40 citations
TL;DR: In this paper, the yttrium alkyl carbene complex was treated with a series of unsaturated organic substrates, a bulky primary amine, and a group 1 metal alkyls to gauge and compare the reactivity of the Y═C carbene and Y−Calkyl bonds.
TL;DR: The yttrium carbene complex [Y(BIPM)(I)(THF)2] (1; BIPM = C(PPh2NSiMe3)2) was reacted with a range of unsaturated substrates as mentioned in this paper.
TL;DR: In this article, the LBut ligand was used to obtain the first U(III) complex for hexane or benzene, which was then used to derive [U(LBut)Cl3], 4, 5, 6, 7, 8, 9, and 10, respectively.
TL;DR: Changing the cocomplexation reaction conditions, the order of reagents added to the reactions mixture, and with the use of a coordinating solvent (tetrahydrofuran) formed the magnesiate complex (L(1))3MgLi(thf) (12).
Abstract: The synthesis and characterization of magnesium and calcium complexes of sterically demanding aminopyridinato ligands is reported. The reaction of the 2-Me3SiNH-6-MeC5H3N (L1H), 2-MePh2SiNH-6-MeC5H...
TL;DR: In this paper, the Schiff base 2]-(E)-(quinolin-3-ylimino)methylphenol (H-QMP) was crystallized in Pc space group and complexed with Ni(II) and Co(II), and calculated activation energies and order of pyrolysis were calculated using Horowitz-Metzger method.
TL;DR: X-ray diffraction studies of 3, 4 and 6 reveal polymeric (3) or tetranuclear (4, 6) structures formed via Tl-S bonds and AuTl or AuTL and AuAu contacts, all of which are luminescent in the solid state, but not in solution, where the metal-metal interactions are no longer present.
Abstract: The polymeric Au/Tl compounds [{Au(C6X5)2}Tl]n (X = Cl, F) react with the crown thioethers 1,4,7-trithiacyclononane ([9]aneS3), 1,5,8,11-tetrathiacyclotetradecane ([14]aneS4), and 1,4,7,10,13,16,19,22-octathiacyclotetracosane ([24]aneS8) in an appropriate molar ratio to afford [{Au(C6X5)2}Tl(L)]2 [L = [9]aneS3, X = Cl (1), F (4); L = [14]aneS4, X = Cl (2), F (5)], [{Au(C6Cl5)2}2Tl2([24]aneS8)]n (3) or [{Au(C6F5)2}2Tl2([24]aneS8)] (6). X-ray diffraction studies of 3, 4 and 6 reveal polymeric (3) or tetranuclear (4, 6) structures formed via Tl–S bonds and Au⋯Tl or Au⋯Tl and Au⋯Au contacts. All the complexes are luminescent in the solid state, but not in solution, where the metal–metal interactions, which are responsible for the luminescence, are no longer present. DFT calculations on representative model systems of complexes 3, 4 and 6 have also been carried out in order to determine the origin of the electronic transitions responsible for their optical properties.
TL;DR: Two complementary approaches are presented for the synthesis of the quinone chromophores of the naphthoquinone ansamycins and related natural products using an improved protocol for the manganese(III) acetate mediated cyclization of 5-aryl-1,3-dicarbonyl compounds to β-naphthols.
Abstract: Two complementary approaches are presented for the synthesis of the quinone chromophores of the naphthoquinone ansamycins and related natural products. The first involves the use of an improved protocol for the manganese(III) acetate mediated cyclization of 5-aryl-1,3-dicarbonyl compounds to β-naphthols, leading to the simple, scalable preparation of building blocks suitable for the synthesis of naturally occurring aminonaphthoquinones. The second approach involves the Diels–Alder reaction of a series of new, ester-containing Danishefsky-type dienes with N-protected aminobenzoquinones to allow more expeditious access to similar intermediates.
TL;DR: In this article, the authors report the extension of the series of {BIPMTMSH}− (BIPMR = C{PPh2NR}2, TMS = trimethylsilyl) derived rare earth methanides by the preparation of [Ln(BIPMMesH)(I)2(THF)] (Ln = Nd, Gd, Tb), 1a-c, in 34-50% crystalline yields via the reaction of [ln(I)3 (THF)3.5
Abstract: We report the extension of the series of {BIPMTMSH}− (BIPMR = C{PPh2NR}2, TMS = trimethylsilyl) derived rare earth methanides by the preparation of [Ln(BIPMTMSH)(I)2(THF)] (Ln = Nd, Gd, Tb), 1a–c, in 34–50% crystalline yields via the reaction of [Ln(I)3(THF)3.5] with [Cs(BIPMTMSH)]. Similarly, we have extended the range of {BIPMMesH}− (Mes = 2,4,6-trimethylphenyl) derived rare earth methanides with the preparation of [Gd(BIPMMesH)(I)2(THF)2], 3, (49%) and [Yb(BIPMMesH)(I)2(THF)], 4, (26%), via the reaction of [Ln(I)3(THF)3.5] with [{K(BIPMMesH)}2]. Attempts to prepare dysprosium and erbium analogues of 3 or 4 were not successful, with the ion pair species [Ln(BIPMMesH)2][BIPMMesH] (Ln = Dy, Er), 5a–b, isolated in 31–39% yield. The TMEDA (N',N',N",N"-tetramethylethylenediamine) adducts [Ln(BIPMMesH)(I)2(TMEDA)] (Ln = La, Gd), 6a–b, were prepared in quantitative yield via the dissolution of [La(BIPMMesH)(I)2(THF)] or 3 in a TMEDA/THF solution. The reactions of [Ln(BIPMMesH)(I)2(THF)] [Ln = La, Ce, Pr, and Gd (3)] or 6a–b with a selection of bases did not afford [La(BIPMMes)(I)(S)n] (S = solvent) as predicted, but instead led to the isolation of the heteroleptic complexes [Ln(BIPMMes)(BIPMMesH)] (Ln = La, Ce, Pr and Gd), 7a–d, in low yields due to ligand scrambling.
TL;DR: On proceeding from lithium to sodium to potassium there is an increase in hapticity of the binding of the carbazol-9-yl ligands to the metal cations, mirroring the increasing ionic bonding character in these compounds.
Abstract: The solid state structures of alkali metal complexes of the 1,3,6,8-tetra-tert-butylcarbazol-9-yl (tBu4carb–) ligand are compared. Lithium complex [tBu4carbLi]2 ([1]2) is a dimer in the solid state featuring a planar LiNLiN rhomboid ring, with the differing Li–N distances within the ring due to the effects of σ- and π-interactions. Recrystallization of lithium, sodium, and potassium complexes of the 1,3,6,8-tetra-tert-butylcarbazol-9-yl ligand from THF leads to the formation of tBu4carbLi(THF)2 (1·2THF), tBu4carbNa(THF)3 (2·3THF), and tBu4carbK(THF)4 (3·4THF), respectively, in the solid state. For these THF adducts, on proceeding from lithium to sodium to potassium there is an increase in hapticity of the binding of the carbazol-9-yl ligands to the metal cations, mirroring the increasing ionic bonding character in these compounds.
TL;DR: Investigation of the structural, electrochemical, spectroscopic, and spectroelectrochemical properties of the isomers of N,N'-bis(alkyl)diadamantylthio-3,4,9,10-perylenetetracarboxylic acid diimide reveal a sequence of electrochemically and chemically reversible reduction processes for both isomers.
Abstract: The synthesis and separation of the 1,6- and 1,7- isomers of N,N′-bis(alkyl)diadamantylthio-3,4,9,10-perylenetetracarboxylic acid diimide are reported. Investigations of the structural, electrochemical, spectroscopic, and spectroelectrochemical properties of the isomers reveal a sequence of electrochemically and chemically reversible reduction processes for both isomers. Three X-ray crystal structures are reported including a pair of 1,6- and 1,7-isomers demonstrating the twist of the perylene core in the solid state. Our studies thoroughly characterize the mono- and direduced states of the two isomers allowing unequivocal characterization of the reduced species by UV–vis and IR spectroscopic measurements. EPR studies also allow direct identification of the monoreduced PTCDI species and spectroscopic measurements confirm the delocalization of electronic density around the carbonyl moieties of the reduced species.
TL;DR: A sodium analogue with medicinally important dicoumarol ligand and Coumarin compound with sodium was observed to be less cytotoxic than the ligand, its LD50 value never dropped below 60%.
Abstract: Enormous interest had been paid to the coordination chemistry of alkali and alkaline metal ions because of their role inside body viz; their Li+/Na+ exchange inside the cell lead to different diseases like neuropathy, hypertension, microalbuminuria, cardiac and vascular hypertrophy, obesity, and insulin resistance. It has been presumed that alkali metal ions (whether Na+ or K+) coordinated to chelating ligands can cross the hydrophobic cell membrane easily and can function effectively for depolarizing the ion difference. This unique function was utilized for bacterial cell death in which K+ has been found coordinated valinomycin (antibiotic). Distinct sodium adduct (1) with dicoumarol ligand, 4-Hydroxy-3-[(4-hydroxy-2-oxo-4a,8a-dihydro-2H-chromen-3-yl)-phenyl-methyl]-chromen-2-one (L) is isolated from the saturated solution of sodium methoxide. Single crystal X-ray diffraction studies of the adduct reveals that sodium is in the form of cation attached to a methoxide, methanol and a dicoumarol ligand where carbonyl functional groups of the coumarin derivative are acting as bridges. The sodium compound (1) is also characterized by IR, 1H-NMR, and 13C{1H}-NMR spectroscopic techniques. The composition is confirmed by elemental analysis. DFT study for 1 has been carried out using B3LYP/6-13G calculations which shown the theoretical confirmation of the various bond lengths and bond angles. Both the compounds were studied subsequently for the U2OS tumoricidal activity and it was found that L has LD50 value of 200 μM whereas the sodium analog cytotoxicity did not drop down below 60%. A sodium analogue (1) with medicinally important dicoumarol ligand (L) has been reported. The crystal structure and DFT study confirm the formation of cationic sodium compound with dicoumarol. The ligand was found more active than the sodium analog attributed to the instability of 1 in solution state. Coumarin compound with sodium was observed to be less cytotoxic than the ligand, its LD50 value never dropped below 60%.
TL;DR: The synthesis and characterization of the first series of low-coordinate bis(terphenyl) complexes of the Group 12 metals are described, and the results of DFT calculations are in good agreement with the solid-state configurations and support the spectroscopic measurements, which indicate several conformers in solution.
Abstract: The synthesis and characterization of the first series of low-coordinate bis(terphenyl) complexes of the Group 12 metals, [Zn(2,6-Naph2 C6 H3 )2 ] (1), [Cd(OEt2 )(2,6-Naph2 C6 H3 )2 ] (2) and [Hg(OEt2 )(2,6-Naph2 C6 H3 )2 ] (3) (Naph=1-C10 H7 ) are described. The naphthyl substituents of the terphenyl ligands confer considerable steric bulk, and as a result of limited flexibility introduce multiple conformations to these unusual systems. In the solid state, complex 1 features a two-coordinate Zn centre with the ligands oriented in a syn/anti conformation, whereas the three-coordinate distorted T-shaped complexes 2 and 3 feature the ligands in the syn/syn configurations. The results of DFT calculations are in good agreement with the solid-state configurations for these complexes and support the spectroscopic measurements, which indicate several conformers in solution.
TL;DR: The reaction between sterically demanding m-terphenyl lithiate complexes and cadmium dihalides yields unusual cubanes where changes in ligand bulk afford different formulations, in particular a rare heterodicubane structure.
TL;DR: In this paper, the reaction of a bis-imidazole ligand, N,N′-bis(3-(1-IMidazolyl)propyl)-1,4,5,8-naphthalene-tetracarboxylicdiimide (BIPNDI), with either Mn(NO3)2 or Cu(NO 3)2 affords coordination polymers of formula {[Mn(BIPNDi)3]-NO3]∞ or [M(BIP NDI)2]-∞ (M
Abstract: The reaction of a bis-imidazole ligand, N,N′-bis(3-(1-imidazolyl)propyl)-1,4,5,8-naphthalene-tetracarboxylicdiimide (BIPNDI), with either Mn(NO3)2 or Cu(NO3)2 affords coordination polymers of formula {[Mn(BIPNDI)3](NO3)2}∞ or [M(BIPNDI)2(NO3)2]∞ (M = Mn or Cu). Single crystal X-ray diffraction studies confirm the structures of supramolecular isomers of {[Mn(BIPNDI)3](NO3)2}∞ (1,2), both of which contain two-dimensional coordination polymer sheets, and a one-dimensional coordination polymer [Mn(BIPNDI)2(NO3)2]∞ (3). Reaction of either Mn(NO3)2 or Cu(NO3)2 with BIPNDI exploiting rapid precipitation affords sub-micron coordination particles of either rod-shaped (4, Mn) or spherical (5, Cu) morphology depending on the metal salt used. SEM and DLS studies were used to probe the morphology and solution behaviour of the coordination particles. Spectroscopic investigations indicate that the rod-shaped, Mn-based particles comprise two-dimensional coordination polymers in contrast to the spherical, Cu-based particles which are composed of one-dimensional coordination polymers.
TL;DR: In this paper, the structures of two porphyrin-based metal-organic frameworks are reported, where the reaction of a carbäoxylic acid functionalised porphrin with Mn(NO3)2 gives rise to either a one-dimensional or a two-dimensional framework structure depending on the reaction solvent employed.
Abstract: Abstract The structures of two porphyrin-based metal-organic frameworks are reported. The reaction of a carbäoxylic acid functionalised porphyrin with Mn(NO3)2 gives rise to either a one-dimensional or a two-dimensional framework structure depending on the reaction solvent employed. 1 (a = 8.3080(5) Å, b = 14.4466(10) Å, c = 21.8737(14) Å, α = 99.182(6)°, β = 94.118(5)°, γ = 92.562(5)°, P-1, R1 = 0.0894, wR2 = 0.2850) consists of one-dimensional coordination polymers linked through hydrogen-bonded porphyrin molecules leading to a two-dimensional array. In contrast 2 (a = 13.6852(6) Å, b = 41.1655(15) Å, c = 15.4535(6) Å, β = 109.954(5)°, P21/c, R1 = 0.1218, wR2 = 0.3806) consists of two-dimensional sheets, constructed from dinuclear Mn(II) clusters and bridging porphyrin ligands, which, as in 1, are linked through hydrogen-bonded porphyrin molecules but in this case leading to a three-dimensional array. In both structures it is notable that the porphyrin molecules do not bind the Mn(II) cations through the macrocyclic carity, rather both structures.
TL;DR: The journal covers scientific developments based on experimental studies as well as those based on theoretical approaches, including crystal structure prediction, structure–property relationships and database analysis, and is the forum for publication of contributions on these topics.
Abstract: Acta Crystallographica Section B celebrates its 45th birthday in 2013, having emerged from the separation of the single journal Acta Crystallographica into Sections A and B in 1968 A further split in 1983 yielded three journals, namely Section A: Foundations of Crystallography, Section B: Structural Science and Section C: Crystal Structure Communications The possibilities for depth and breadth of structural description and discussion have been important features available to authors in Acta Crystallographica Section B The journal publishes scientific articles related to the structural science of compounds and materials in the widest sense Knowledge of the arrangements of atoms, including their temporal variations and dependencies on temperature, pressure and other conditions, is often the key to understanding physical and chemical phenomena and is crucial for the design of new compounds, materials and supramolecular devices Acta Crystallographica Section B is the forum for publication of contributions on these topics The journal covers scientific developments based on experimental studies as well as those based on theoretical approaches, including crystal structure prediction, structure–property relationships and database analysis