Synthesis of a Hexameric Magnesium 4-pyridyl Complex with Cyclohexane-like Ring Structure via Reductive C-N Activation

The reaction of [{(^Arnacnac)Mg}₂] (^Arnacnac = HC{MeC(NAr)}₂, Ar = 2,6-diisopropylphenyl, Dip, or 2,6-diethylphenyl, Dep) with 4-dimethylaminopyridine (DMAP) at elevated temperatures afforded the hexameric magnesium 4-pyridyl complex [{(^Arnacnac)Mg(4-C₅H₄N)}₆] via reductive cleavage of the DMAP C-N bond. The title compound contains a large s-block organometallic cyclohexane-like ring structure comprising tetrahedral (^Arnacnac)Mg nodes and linked by linear 4-pyridyl bridging ligands, and the structure is compared with other ring systems. [(^Dipnacnac)Mg(DMAP)(NMe₂)] was structurally characterised as a by-product.

A regioselectively 1,1',3,3'-tetrazincated ferrocene complex displaying core and peripheral reactivity

Regioselective 1,1',3,3'-tetrazincation [C-H to C-Zn(tBu)] of ferrocene has been achieved by reaction of a fourfold excess of di-t-butylzinc (tBu₂Zn) with sodium 2,2,6,6-tetramethylpiperidide (NaTMP) in hexane solution manifested in the trimetallic iron-sodium-zinc complex [Na₄(TMP)₄Zn₄(tBu)₄{(C₅H₃)₂Fe}], 1. X-ray crystallographic studies supported by DFT modelling reveal the structure to be an open inverse crown in which two [Na(TMP)Zn(tBu)Na(TMP)Zn(tBu)]²⁺ cationic units surround a {(C₅H₃)₂Fe}^4- tetraanion. Detailed C₆D₆ NMR studies have assigned the plethora of ¹H and ¹³C chemical shifts of this complex. It exists in a major form in which capping and bridging TMP groups interchange, as well as a minor form that appears to be an intermediate in this complicated exchange phenomenon. Investigation of 1 has uncovered two distinct reactivities. Two of its peripheral t-butyl carbanions formally deprotonate toluene at the lateral methyl group to generate benzyl ligands that replace these carbanions in [Na₄(TMP)₄Zn₄(tBu)₂(CH₂Ph)₂{(C₅H₃)₂Fe}], 2, which retains its tetrazincated ferrocenyl core. Benzyl-Na π-arene interactions are a notable feature of 2. In contrast, reaction with pyridine affords the crystalline product {[Na·4py][Zn(py*)₂(tBu)·py]}_∞, 3, where py is neutral pyridine (C₅H₅N) and py* is the anion (4-C₅H₄N), a rare example of pyridine deprotonated/metallated at the 4-position. This ferrocene-free complex appears to be a product of core reactivity in that the core-positioned ferrocenyl anions of 1, in company with TMP anions, have formally deprotonated the heterocycle.

Novel mono- and bimetallic organotin(iv) compounds as potential linkers for coordination polymers

Organotin(iv) compounds might be used as linkers for building coordination polymers as suggested by the isolation of [{2-(OCH)C₆H₄}Me₂SnO(O)CC₅H₄N-4]ZnTPP.

Triphenylbismuth(v) di[(iso)nicotinates] - transmetallation agents or divergent organometalloligands? First organobismuth(v)-based silver(i) coordination polymers

The reaction of Ph₃BiCl₂ with alkali salts of isonicotinic and nicotinic acids afforded Ph₃Bi[O(O)CC₅H₄N-4]₂ (1) and Ph₃Bi[O(O)CC₅H₄N-3]₂ (2), respectively, which were characterized by multinuclear NMR spectroscopy in solution, mass spectrometry and IR spectroscopy in the solid state. Their molecular structures were established by single-crystal X-ray diffraction. For both 1 and 2 the molecules contain a trigonal bipyramidal C₃BiO₂ core, with the phenyl groups in equatorial positions. The potential use of 1 and 2 as ditopic organometalloligands was investigated. The reaction of 1 or 2 with Me₃SnCl (1 : 2 molar ratio) resulted in carboxylato ligand exchange and the formation of Me₃Sn[O(O)CC₅H₄N-4] (3) and Me₃Sn[O(O)CC₅H₄N-3] (4) besides Ph₃BiCl₂. The crystals of both 3 and 4 contain 1-D coordination polymers built through intermolecular N → Sn interactions. The treatment of Ni[S₂P(OⁱPr)₂]₂ with 1 and 2, respectively, resulted, in addition to di(carboxylato)nickel(ii) derivatives, in isolation of Ph₃Bi and the disulphane [(ⁱPrO)₂P(S)S]₂. New coordination polymers were obtained by reacting 1 and 2 with various silver(i) salts: [Ag{Ph₃Bi[O(O)CC₅H₄N-4]₂}(OTf)] (5), [Ag{Ph₃Bi[O(O)CC₅H₄N-3]₂}(OTf)]·CH₂Cl₂ (6·CH₂Cl₂), [Ag{Ph₃Bi[O(O)CC₅H₄N-4]₂}](SbF₆)·2THF (7·2THF), [Ag{Ph₃Bi[O(O)CC₅H₄N-3]₂}](SbF₆)·CH₂Cl₂ (8·CH₂Cl₂) and [Ag{Ph₃Bi[O(O)CC₅H₄N-3]₂}(NO₃)]·CH₂Cl₂ (9·CH₂Cl₂). The crystal structures of 5 and 6 can be described as 1-D chains linked by triflate bridges in pairs of chains and 2-D networks, respectively. Compound 7 features a 2-D grid-like topology of the network, with tecton 1 acting as a tridentate ligand through both nitrogen and one oxygen atoms. The linker 2 molecules adopt either cis (compound 6) or trans (compounds 8 and 9) conformation. Complexes 8 and 9 are 1-D chain polymers exhibiting zig-zag and wavy motifs, respectively. The dimensionality of the structures is extended by the presence of supramolecular interactions (ππ, AgAg, AgO).

Organic co-crystals of 1,3-bis(4-pyridyl)azulene with a series of hydrogen-bond donors

1,3-Bis(4-pyridyl)azulene has been employed as a hydrogen bond acceptor to construct two-component organic cocrystals.

Molecular tectonics: heterometallic coordination networks based on a Pt(II) organometallic metallatecton

Combinations of a neutral organometallic tecton based on a square planar Pt(ii) complex bearing two triphenylphosphine groups and two 4-ethynylpyridyl coordinating moieties in trans positions, with various metal halides (MX2, M = Co(ii), Ni(ii), Cd(ii), X = Cl(-) or Br(-)) lead to the formation of 2D grid type heterobimetallic coordination networks in the crystalline phase.