Some Considerations on Modeling Heat and Mass Transfer in Porous Media

In this paper some considerations are presented about the equations needed to set up a model of the process of heat and mass transfer in porous media. A clear classification is made of the various types of equations used and of their physical meaning. Special attention is paid to the thermodynamic equilibrium equations and to their derivation since they are too often taken for granted. The importance of the various transport mechanisms (of mass and energy) is analyzed and the consequences that can arise when some term is neglected are indicated.     

Poly[[μ2‐4,4′‐bipyridine‐di‐μ3‐sulfito‐dizinc(II)] monohydrate]

The title compound, {[Zn₂(SO₃)₂(C₁₀H₈N₂)]·H₂O}_n, is a two‐dimensional polymer built up of a [ZnSO₃]_n chain evolving around a 2₁ axis and inter­connected by a 4,4′‐bipyridine spacer. The resulting two‐dimensional structures are linked, in turn, by hydrogen bonding mediated by the solvent water mol­ecule. The organic ligand lies on a centre of symmetry located on the mid‐point of the bond between the rings, while the solvent water mol­ecule is halved by a twofold axis passing through the O atom.     

Two oxo complexes with tetra­nuclear [Fe4(μ3‐O)2]8+ and trinuclear [Fe3(μ3‐O)]7+ units

Two new oxo complexes, namely hexa‐μ₂‐acetato‐acetato­aquabis­(di‐3‐pyridylamine)di‐μ₃‐oxo‐tetra­iron(III) chloride mono­hydrate ethanol 1.25‐solvate, [Fe₄(C₂H₃O₂)₇O₂(C₁₀H₉N₃)₂(H₂O)]Cl·1.25C₂H₆O·H₂O, (I), containing a tetra­nuclear [Fe₄(μ₃‐O)₂]⁸⁺ unit, and 2‐methyl­imidazolium hexa‐μ₂‐acetato‐acetatodiaqua‐μ₃‐oxo‐triiron(III) chloride dihydrate, (C₄H₇N₂)[Fe₃(C₂H₃O₂)₇O(H₂O)₂]Cl·2H₂O, (II), with a trinuclear [Fe₃(μ₃‐O)]⁷⁺ unit, are presented. Both structures are formed by two well differentiated entities, viz. a compact isolated cluster composed of Fe^III ions coordinated to O²⁻ and CH₃CO₂⁻ anions, and an external group formed by a central Cl⁻ ion surrounded by different solvent groups to which the anion is bound through hydrogen bonding. In the case of (I), charge balance cannot be achieved within the groups, so the structure is macroscopically ionic; in the case of (II), in contrast, each group is locally neutral owing to the inter­nal compensation of charges. The trinuclear complex crystallizes with the metal cluster, chloride anion and 2‐methyl­imidazolium cation bisected by a crystallographic mirror plane.     

An anisaldehyde sodium bisulfite derivative: poly[[μ4‐(hydroxy)(4‐methoxyphenyl)methanesulfonato]sodium]

The title complex, [Na(C₈H₉O₅S)]_n, is polymeric and consists of broad layers parallel to (100) made up of an inner hydrophilic core of Na⁺ cations and polar SO₃C(OH)– groups, padded on both sides by two hydrophobic layers of pendant methoxyphenyl groups. The Na⁺ cations in the inner core are six‐coordinated into highly distorted NaO₆ octahedra by four symmetry‐related (hydroxy)(4‐methoxyphenyl)methanesulfonate anions, leading to a tightly woven two‐dimensional structure. While there are some hydrogen bonds providing interplanar cohesion, interactions between adjacent layers are weak hydrophobic ones. The present compound appears to be the first reported structure containing the (hydroxy)(4‐methoxyphenyl)methanesulfonate ligand.     

Aripiprazole salts. III. Bis(aripiprazolium) oxalate–oxalic acid (1/1)

The asymmetric unit of the title salt [systematic name: bis(4‐(2,3‐dichlorophenyl)‐1‐{4‐[(2‐oxo‐1,2,3,4‐tetrahydroquinolin‐7‐yl)oxy]butyl}piperazin‐1‐ium) oxalate–oxalic acid (1/1)], 2C₂₃H₂₈Cl₂N₃O₂⁺·C₂O₄²⁻·C₂H₂O₄, consists of one protonated aripiprazole unit (HArip⁺), half an oxalate dianion and half an oxalic acid molecule, the latter two lying on inversion centres. The conformation of the HArip⁺ cation differs from that in other reported salts and resembles more the conformation of neutral Arip units in reported polymorphs and solvates. The intermolecular interaction linking HArip⁺ cations is also similar to those in reported Arip compounds crystallizing in the space group P, with head‐to‐head N—H...O hydrogen bonds generating centrosymmetric dimers, which are further organized into planar ribbons parallel to (01). The oxalate anions and oxalic acid molecules form hydrogen‐bonded chains running along [010], which `pierce' the planar ribbons, interacting with them through a number of stronger N—H...O and weaker C—H...O hydrogen bonds, forming a three‐dimensional network.