Supramolecular Synthons in Crystal Engineering. 4. Structure Simplification and Synthon Interchangeability in Some Organic Diamondoid Solids¹

Abstract

Any organic crystal structure can be simplified to a network wherein the molecules are the nodes and the supramolecular synthons are the node connections. This approach to crystal engineering is illustrated in this paper with reference to organic structures based on the diamond network. By introducing N‚ ‚ ‚Br synthons into this network, a 2-fold-catenated structure is obtained for the 1:1 complex between hexamethylenetetramine (HMT) and CBr 4 . The use of C-H‚ ‚ ‚N mediated synthons in the same network results in the 1:2 complex of 1,3,5,7-tetrabromoadamantane (AdBr 4 ) with HMT. Further structural flexibility is achieved by the interchange of molecular and supramolecular synthons. Accordingly, the diamond-based crystal structures of tetrakis-(4-bromophenyl)methane and the 1:1 molecular complex of tetraphenylmethane and CBr 4 are very similar. This near-identity arises because of the structural equivalence of the CBr 4 molecular synthon and the Br 4 supramolecular synthon and the ability of the CBr 4 molecule to participate in Br‚ ‚ ‚phenyl interactions. In general, there is much topological correspondence between organic and inorganic crystal structures, and this can be utilized in the description of organic crystal structures as networks. Such a depiction is of much practical utility and is different from Kitaigorodskii's model which distinguishes fundamentally between molecular and crystal structure. In the network model, molecular and supramolecular synthons are interchangeable within the same network structure.

Tricarbonylmanganese(I) derivatives of [Di(pyrazolyl)(2-pyridyl)methyl]aryl scorpionates

“…Silica gel (230-400 mesh, 40-63 lm) for chromatographic separations was purchased from Fisher Scientific. Thionyl chloride, 1-H-pyrazole (Hpz), 1-H-4-methylpyrazole, (Hpz 4Me ), 2-benzoylpyridine, AgBF 4 , AgPF 6 , and Mn(CO) 5 Br were purchased from Aldrich Chemicals. Anhydrous CoCl 2 was used as purchased from Strem Chemicals.…”

“…These ligands, especially those in which we link two or more of the tris(pyrazolyl)methane units in a single (multitopic) ligand, offer substantial structural diversity. The multiple coordination modes and ability of these ligands to support important non-covalent interactions such as weak hydrogen bonds [3], p-p stacking [4], X-HÁ Á Áp interactions (X = O, N, C) [5], and interhalogen interactions [6] is responsible for the structural diversity in their metal complexes. In our previous chemistry on multitopic ligands, we have mainly employed semi-rigid linking groups, such as in C 6 H 6 À n [CH 2 OCH 2 C(pz) 3 ] n (n = 2, 3,4,6) in the formation of discrete coordination complexes and coordination polymers [7].…”

“…The multiple coordination modes and ability of these ligands to support important non-covalent interactions such as weak hydrogen bonds [3], p-p stacking [4], X-HÁ Á Áp interactions (X = O, N, C) [5], and interhalogen interactions [6] is responsible for the structural diversity in their metal complexes. In our previous chemistry on multitopic ligands, we have mainly employed semi-rigid linking groups, such as in C 6 H 6 À n [CH 2 OCH 2 C(pz) 3 ] n (n = 2, 3,4,6) in the formation of discrete coordination complexes and coordination polymers [7]. We have also reported the syntheses of heteroscorpionate ligands based on di(pyrazolyl)(2-pyridyl)methane units, including a fixed geometry ligand, m-C 6 H 4 [C(pz) 2 (2-py)] 2 (pz = pyrazolyl ring, py = pyridyl ring) [8].…”

Synthesis and Characterization of the Td-Type Clathrates: M(2,2-DIMETHYL-1,3-DIAMINOPROPANE)M'(CN)4.2C6H6 (M= Mn or Cd, M'= Cd, Hg or Zn)

“…The superstructure exhibits new structural, physical and chemical properties that are excellent to the superstructure and have allowed to utilize the target identification and synthetic methodology as parts of crystallography [3,4]. The structure of the Hofmann-Td-type clathrates, Cd(NH3)2M´(CN)4.2C6H6 (M´ = Cd or Hg) has already been determined [5].…”

C–H···O and C–H···N Hydrogen Bond Networks in the Crystal Structures of Some 1,2-Dihydro-N-aryl-4,6-dimethylpyrimidin-2-ones

“…An advantage of the network representation is that topological similarities between crystal structures are e!ectively revealed, so that relationships may be found between crystal structures of widely di!ering species (12). Many examples are known but we mention here just two, from the Hyderabad group*1,3,5,7-tetrahydroxyadamantane and CsCl have the same network topology (13) while tetrakis(4-bromophenyl)methane and the 1 : 1 molecular complex of tetraphenylmethane and CBr are nearly isostructural (14).…”