Structural variations in layered alkaline earth metal cyclohexyl phosphonates

Two series of alkaline earth metal cyclohexyl phosphonates, M(C6H11PO3H)2(H2O) (M = Ca, Sr and Ba) (1-3) and M(C6H11PO3)(H2O) (M = Mg, Ca, Sr, and Ba) (4-7) have been synthesized under mild reaction conditions. All new compounds have been characterized using elemental analysis, IR, TGA and powder X-ray diffraction techniques. The molecular structure of compound 2 determined using single crystal X-ray diffraction technique reveals a layered polymeric structure

Facile one-pot synthesis of functionalized organophosphonate esters via ketone insertion into bulky arylphosphites

The reaction of phosphorus trichloride with 2,6-diisopropyl phenol in the presence of LiCl under reflux conditions for 24 h produces a mixture of (ArO)PCl2 and (ArO)2PCl (Ar = 2,6-iPr2C6H3). The hydrolysis of the aryloxy compounds in acetone/H2O results in the formation of two novel phosphonate ester derivatives [(ArO)P(O)(OH)(CMe2OH)] (1) and [(ArO)2P(O)(CMe2OH)] (2), respectively in a moderate yield. The title compounds have presumably formed via acetone insertion to the P-H bonds of (ArO)P(O)(H)(OH) and (ArO)2P(O)(H), respectively, in the presence of HCl produced during the hydrolysis. Compounds 1 and 2 have been characterized by elemental analysis, and ESI-mass, Infrared and NMR spectroscopic techniques. Further, solid state structures of 1 and 2 have been established by single crystals X-ray diffraction studies

First alkaline earth metal 3-aminobenzoate (3-aba) complex: 1-D polymeric [Ca(3-aba)<SUB>2</SUB>(H<SUB>2</SUB>O)<SUB>2</SUB>]<SUB>n</SUB> assembly

The reaction of CaCO3 or CaCl2·2H2O with 3-abaH results in the formation of the first alkaline-earth metal complex of 3-abaH [Ca(3-aba)2(H2O)2]n (1) in good yield. The product has been characterized by elemental analysis, IR, UV-vis and 1H NMR spectral studies, TGA and single crystal X-ray diffraction studies. The molecular structure of 1 is made up of 1-D polymeric chains that are hydrogen-bonded to each other. The Ca2+ ion in 1 is surrounded by eight oxygen atoms in a distorted square-antiprismatic geometry

First alkaline earth metal 3-aminobenzoate (3-aba) complex: 1-D polymeric [Ca(3-aba)2(H2O)2]n assembly

The reaction of CaCO3 or CaCl2·2H2O with 3-abaH results in the formation of the first alkaline-earth metal complex of 3-abaH [Ca(3-aba)2(H2O)2]n (1) in good yield. The product has been characterized by elemental analysis, IR, UV–vis and 1H NMR spectral studies, TGA and single crystal X-ray diffraction studies. The molecular structure of 1 is made up of 1-D polymeric chains that are hydrogen-bonded to each other. The Ca2+ ion in 1 is surrounded by eight oxygen atoms in a distorted square-antiprismatic geometry.© Elsevie

Reactions of 1,3,5-benzenetricarboxylic acid with Zn(II) ion in the presence of added amines: Isolation and structure determination of zinc coordination polymers with tetrahedral and octahedral zinc centres^§,†

2267-2276The formation of two metal-organic coordination polymers and an organic supramolecular network based on 1,3,5-benzenetricarboxylic ac id (H3BTC) is reported. While [Zn3(BTC)2(DMP)6 2.5H2O] (1) is formed by the addition of zinc acetate and 3,5-dimethylpyrazole (DMP) to H3BTC, the addition of zinc acetate to 4-aminopyridine and H3BTC results in previously reported [Zn3(BTC)2.12H2O] (2). On the other hand, the interaction of H3BTC with ZnSO4 in the presence of pi-perazine (PIP) leads to the formation of [H2BTC]2[H2PIP] (3) as soluble single crystals in addition to un insoluble zinc-BTC- piperazine complex with unknown composition. The solid -state structures as determined by single crystal X-ray diffraction studies reveal that compounds 1-3 form 3-D polymeric networks with the aid of extensive hydrogen bonding. In 1, the adjacent dimeric units of [(DMP)4Zn2(BTC)2] are bridged by [Zn(DMP)2] units to form a polymeric chain structure. These chains are in turn linked to each other through hydrogen bonding to form a 2-D sheet network. The 2-D sheets are held together by weak π-π interactions to form a 3-D network. Compound 2 is made up of a zig-zag chain of alternating BTC3- ion and Zn(H2O)4 octahedral units. These chains are held together by numerous hydrogen bonding interactions resulting in a porous solid. The supramolecular assembly in 3 can be described as a host-guest complex in which the hydrogen bonded [H2BTC-]n network hosts the piperazinium cations

Microwave assisted solid-state synthesis of functional organotin carboxylates from sterically encumbered 3,5-di-tert-butylsalicylic acid

Microwave assisted solid-state reaction between equimolar quantities of sterically encumbered 3,5-di-tert-butylsalicylic acid (H2-DTBSA) and n-butylstannoic acid results in the formation of hexameric drum shaped stannoxane [nBuSn(O)(H-DTBSA)]6 (1). Synthesis of 1 could not be achieved under normal thermal conditions or mechanical grinding. However, the azeotropic removal of water produced in the reaction of nBu2SnO with 3,5-di-tert-butyl salicylic acid in benzene yielded the tetrameric ladder shaped stannoxane [{nBu2Sn(H-DTBSA)}2O]2 (2), which could also be synthesized in better yields by microwave irradiation as in the case of 1. Compounds 1 and 2 have been characterized by elemental analysis, IR, MALDI-MS and NMR (1H and 13C) spectroscopy. The structures of compound 1 and 2 are determined by single crystal X-ray diffraction techniques. Compound 1 is hexameric with a Sn6O6 drum core while compound 2 forms a ladder structure with three Sn2O2 rings, both decorated with –OH functionalities on the exterior of the polyhedral structure. While the formation of 1 from n-butylstannoic acid is straightforward, the formation of 2 from nBu2SnO (and not a cyclic structure similar to 3, where the phenolic oxygen also coordinates to tin) can be understood in terms of the increased steric hindrance in DTBSA for the phenolic protons to react with tin.© Elsevie

Structural diversity and supramolecular aggregation in calcium, strontium, and barium salicylates incorporating 1,10-phenanthroline and 4,4'-bipyridine: probing the softer side of group 2 metal ions with pyridinic ligands

Group 2 metal complexes [Ca(SA)2(phen)]n (1), [Sr2(SA)4(phen)4] (2), and [Ba(SA)2(phen)2]n (3) (SA = salicylate) have been obtained by the addition of 1,10-phenanthroline (phen) to the corresponding metal salicylates, while the bipyridine derivatives {[Ca3(SA)6(H2O)4](4bpy)2}n (4), {[Sr(SA)2(H2O)3](4bpy)1.5(H2O)}n (5), and {[Ba(SA)2(H2O)3]-(4bpy)1.5(H2O)}n (6) have been synthesized starting from the respective metal carbonates, salicylic acid (SA-H), and 4,4'-bipyridine (4bpy). The new compounds have been characterized by elemental analysis, pH measurements, thermal analysis, and spectroscopic measurements (IR, NMR, ultraviolet, and fluorescence). Molecular structure determination by single-crystal X-ray diffraction has been carried out for all the compounds. The thermal analysis studies indicate the loss of coordinated and/or lattice water molecules below 200 &#176;C in 4-6 and the absence of any coordinated or uncoordinated water molecules in compounds 1-3. Compounds 1 and 3-6 exist as one-dimensional polymers while compound 2 crystallizes as a discrete dimer. Considerable variations have been observed in the molecular structures of 1-6 in terms of the geometry around the metal, the binding mode of salicylate, and the coordination behavior of the pyridine ligand. Calcium ion is hexacoordinated in 1, while in 4 both hexa- and heptacoordinated calcium ions are simultaneously present. Strontium exhibits coordination numbers of nine and eight in 2 and 5, respectively. The barium ions in 3 and 6 assume coordination numbers of eight and seven, respectively. While the OH group of the salicylate ligand does not directly bind the metal in 1-3, it coordinates to the metal ions in complexes in 4-6 in the un-ionized form. The 4bpy molecules show no direct ligation to the metal in 4-6; the phen ligands in 1-3, however, occupy one side of the coordination sphere around the metal. The presence of additional O-H&#183;&#183;&#183;O, C-H&#183;&#183;&#183;O, and N-H&#183;&#183;&#183;O hydrogen bonding and &#8719;-&#8719; stacking in these compounds results in the formation of polymeric structures. The results obtained for the calcium complexes in this study have been compared with the available data in structural calcium chemistry with the aid of a detailed analysis of the Cambridge Structural Database

Microwave assisted solid-state synthesis of functional organotin carboxylates from sterically encumbered 3,5-di-tert-butylsalicylic acid

Microwave assisted solid-state reaction between equimolar quantities of sterically encumbered 3,5-di-tert-butylsalicylic acid (H2-DTBSA) and n-butylstannoic acid results in the formation of hexameric drum shaped stannoxane [nBuSn(O)(H-DTBSA)]6 (1). Synthesis of 1 could not be achieved under normal thermal conditions or mechanical grinding. However, the azeotropic removal of water produced in the reaction of nBu2SnO with 3,5-di-tert-butyl salicylic acid in benzene yielded the tetrameric ladder shaped stannoxane [{nBu2Sn(H-DTBSA)}2O]2 (2), which could also be synthesized in better yields by microwave irradiation as in the case of 1. Compounds 1 and 2 have been characterized by elemental analysis, IR, MALDI-MS and NMR (1H and 13C) spectroscopy. The structures of compound 1 and 2 are determined by single crystal X-ray diffraction techniques. Compound 1 is hexameric with a Sn6O6 drum core while compound 2 forms a ladder structure with three Sn2O2 rings, both decorated with –OH functionalities on the exterior of the polyhedral structure. While the formation of 1 from n-butylstannoic acid is straightforward, the formation of 2 from nBu2SnO (and not a cyclic structure similar to 3, where the phenolic oxygen also coordinates to tin) can be understood in terms of the increased steric hindrance in DTBSA for the phenolic protons to react with tin.© Elsevie

Octameric and decameric aluminophosphates

The title compounds are not only among the largest molecular aluminophosphates synthesized thus far, but are also rare polyhedral cages that contain AlO4, AlO5, and AlO6 coordination geometries (see structure; red O, blue Al, pink P). The cores of these aluminophosphates represent new structural building units (SBUs) in zeolite chemistry

Formation of one-dimensional water inside an organic solid: supramolecular architectures derived by the interaction of aminobenzoic acids with nitrogen bases and H<SUB>2</SUB>SO<SUB>4</SUB>

Three different organic supramolecular architectures derived from 2- and 3-aminobenzoic acids are reported. 3-Aminobenzoic acid (3-ABA-H) forms complexes with 2-aminopyridine (2-AP) and 1,4-diazabicyclo[2,2,2]octane (DABCO) to yield [(3-ABA)(2-AP-H)] (1) and [(3-ABA)(DABCO-H)(H2O)2] (2), respectively. 2-Aminobenzoic acid (2-ABA-H), on the other hand, interacts with sulfuric acid in the presence of V2O5 to yield [(2-ABA-H2)4(HSO4)2(SO4)(H2O)] (3). Compounds 1-3 have been obtained as single crystals and characterized by elemental analysis, IR and 1H NMR spectroscopy, and single-crystal X-ray diffraction techniques. Compound 1 crystallizes in the monoclinic space group P21/c [a = 9.6455(5) &#197;, b = 10.9229(7) &#197;, c = 11.976(2) &#197;, &#946; = 112.932(7)&#176;, R1 = 0.0363]. It is an infinite two-dimensional layered polymer in which the carboxylic acid hydrogen is transferred to the pyridine nitrogen. Compound 2 crystallizes in the monoclinic space group Cc [a = 14.2950(9), b = 11.7660(7), c = 9.813(1) &#197;, &#946;= 116.214(7)&#176;, R1 = 0.0492], in which one of the DABCO nitrogens is protonated by accepting the proton of the carboxylic acid. The two water molecules present in the asymmetric part of the unit cell of 2 form an unusual assembly of water to form a one-dimensional polymeric chain through hydrogen bonding. Compound 3 crystallizes in the triclinic space group P&#8593; [a = 7.470(1), b = 11.128(1), c = 22.552(2) &#197;, a = 85.075(7)&#176;, &#946; = 88.712(9)&#176;, &#947; = 72.509(8)&#176;, R1 = 0.0573]. A number of N-H&#183;&#183;&#183;O, O-H&#183;&#183;&#183;O, and/or N-H&#183;&#183;&#183;N hydrogen bonds are prevalent in the structures of 1-3, resulting in the formation a two- or three-dimensional supramolecular architecture in these compounds