Charge-Assisted Hydrogen-Bonded Networks of NH4+ and [Co(NH3)6]3+ with the New Linker Anion of 4-Phosphono-Biphenyl-4′-Carboxylic Acid

Abstract

Abstract:The new linker molecule 4-phosphono-biphenyl-4 1 -carboxylic acid (H 2 O 3 P-(C 6 H 4 ) 2 -COOH, H 3 BPPA) has been structurally elucidated in hydrogen-bonded networks with the ammonium cation NH 4 (H 2 BPPA)(H 3 BPPA) (1) and the hexaamminecobalt(III) cation [Co(NH 3 ) 6 ](BPPA)¨4H 2 O (2). The protic O-H and N-H hydrogen atoms were found and refined in the low-temperature single-crystal X-ray structures. The hydrogen bonds in both structures are so-called charge-assisted; that is, the H-bond donor and/or acceptor carry positive and/or negative ionic charges, respectively.The H-bonded network in 1 consists of one formally mono-deprotonated 4-phosphonato-biphenyl-4 1 -carboxylic acid group; that is, a H 2 BPPA´anion and a neutral H 3 BPPA molecule, which together form a 3D hydrogen-bonded network. However, an almost symmetric resonance-assisted hydrogen bond (RAHB) bond [O¨¨¨H = 1.17 (3) and 1.26 (3) Å, O¨¨¨H¨¨¨O = 180 (3)˝] signals charge delocalization between the formal H 2 BPPA´anion and the formally neutral H 3 BPPA molecule. Hence, the anion in 1 is better formulated as [H 2 BPPA¨¨¨H¨¨¨H 2 BPPA]´. In the H-bonded network of 2 the 4-phosphonato-biphenyl-4 1 -carboxylic acid is triply deprotonated, BPPA 3´. The [Co(NH 3 ) 6 ] 3+ cation is embedded between H-bond acceptor groups, -COO´and -PO 3´a nd H 2 O molecules. The incorporation of sixteen H 2 O molecules per unit cell makes 2 an analogue of the well-studied guanidinium sulfonate frameworks.

Revisiting ion-pair interactions in phase transfer catalysis: from ionic compounds to real catalyst systems

“…The outcome regarding the nature of the different interactions upon complexation studied within the iminium-based complexes is far from surprising since it has been previously theoretically described in the literature as “charge-assisted hydrogen bonds”. 34,35…”

“…The outcome regarding the nature of the different interactions upon complexation studied within the iminium-based complexes is far from surprising since it has been previously theoretically described in the literature as "charge-assisted hydrogen bonds". 34,35 3.2.2 Solvent effects. The present investigation was primarily conducted in the gas phase to focus on the characterisation of the nature of the diverse interactions inherent within ionic compounds.…”

Phosphonate-substituted porphyrins as efficient, cost-effective and reusable photocatalysts

“…Phosphonic acids are well-known to form strong hydrogen bonds 38,39 and to promote the formation of networks through a charge-assisted hydrogen bonding. 40,41 In the studied structure, each phosphonate substituent is involved in the formation of two or three hydrogen bonds with phosphonate groups of nearby porphyrin molecules and dimethylammonium cations (Fig. 3).…”

Crystalline multicomponent compounds involving hexaammine cobalt(iii) cations

“…17 The study of crystal structures of multicomponent solids containing hexaammine cobalt(III) is limited. A detailed analysis of the Cambridge Structural Database (CSD version 5.4 + 4 updates) 19 of crystal structures shows the existence of hydrogenbonded metal complexes with [Co(NH 3 ) 6 ] 3+ cations and various derivatives of sulfonate, [20][21][22][23] disulfonate, [24][25][26] and trisulfonate anions, 27 mono-, di-, and tetracarboxylate anions, [28][29][30][31][32][33][34][35][36][37][38] 4-nitrophenolate, 39 ethylenediaminetetraacetate, 40 C 60 fulleride 41 and inorganic anions. [42][43][44] However, there is only one report of a bacterially produced natural carboxylic lasalocid A, which exhibits antibiotic and anticoccidial activities as well as a pronounced cardiovascular effect.…”