Poly[[μ₂-aqua-tetraaquadi-μ₃-malonato-nickel(II)strontium(II)] dihydrate]

Abstract

Key indicators: single-crystal X-ray study; T = 294 K; mean (C-C) = 0.006 Å; R factor = 0.035; wR factor = 0.098; data-to-parameter ratio = 12.5.The unit-cell parameters for the title mixed-metal coordination polymer, {[NiSr(C 3 H 2 O 4 ) 2 (H 2 O) 5 ]Á2H 2 O} n , which is isostructural with its Co-containing analogue, were reported previously [Gil de Muro et al. (1999). Eur. J. Inorg. Chem. pp. 935-943]; the full crystal structure including a description of the hydrogen bonding is reported here. The Sr 2+ ion is bonded to five O atoms from three different malonate dianions and four water molecules, displaying a distorted tricapped trigonal-prismatic coordination geometry. Two malonate dianions, two water molecules and one Ni 2+ ion build up a dianionic [Ni(C 3 H 2 O 4 ) 2 (H 2 O) 2 ] 2À unit incorporating a slightly distorted NiO 6 octahedron, which coordinates to three nearby Sr 2+ ions. This arrangement creates a metal-organic framework having a 20-membered ring with four Ni and six Sr atoms lying in the bc plane. The coordinated and uncoordinated water molecules are responsible for the formation of two D5 hydrogen-bonded water chains within the 20-membered ring and they are linked into an R4 water cluster via two bifurcated O-HÁ Á Á(O,O) links.

Podoplanin Immunopositive Lymphatic Vessels at the Implant Interface in a Rat Model of Osteoporotic Fractures

“…Because of the systemic nature of osteoporosis it is not possible that local acting biomaterials themselves influence the illness but modifying them with drugs, growth factors, organic and inorganic active components might promise success. Recently it has been described that strontium administration was successful for the treatment of osteoporosis [2], [3]. Thus one animal subgroup received an implant with a strontium modification of the CPC.…”

“…The commercially available bone substitution materials are not etiology-adapted and therefore not appropriate for the application in osteoporotic damaged bone. In the last years it has been worked out that modification with strontium [2], [3], bisphosphonate [4] as well as enhanced resorption capacity and changes from solid material to interconnected porous material [5] improves the materials. High resorption capacity goes along with the disposal of the degraded fragments often inserted in cell organelles of macrophages.…”