This foreword introduces some selected papers presented at the 4th Molecular Materials Meeting in Singapore (M3@Singapore) from 14 to 16 January 2014 that was organized by the Institute of Materials Research and Engineering (IMRE) of A*STAR, Singapore. The conference brought together leading researchers in the disciplines of chemistry, materials science, physics, biology, medicine, and engineering to discuss advances in molecular materials and cultivate cross-disciplinary research.

This paper sheds light on a new class of two-dimensional materials beyond graphene: silicene, germanene, and stanene.

This short review highlights recent understanding of the lipase-catalyzed synthesis of flavour-active esters in various systems, including solvent-free, organic solvents, ionic fluids, supercritical fluids, and aqueous media. Mechanisms of reaction are also covered including esterification and transesterification. The biocatalytic synthesis of aroma compounds via enzymatic methods is becoming an integral part of green chemistry.

Non-fluorescent fluorescamine reacts with primary amines to form highly fluorescent products, affording simple, fast, and sensitive quantification of albumin. Chemical reactions of non-fluorescent (A) fluorescamine, (B) 2-methoxy-2,4-diphenyl-3(2H)-furanone, and (C) o-phthaldialdehyde with primary amines form various fluorophores. (D) Highly fluorescent product can be observed under a UV lamp.

Nanocomposite Pd/Fe₃O₄ has been prepared via a coordination-driven approach, and shows efficient catalytic activity towards the reduction reaction of 4-nitrophenol to 4-aminophenol.

We herein report a Cd-based coordination polymer containing three integrated polymeric components: two neutral and entangled two-dimensional (6,3) nets and one zwitterionic one-dimensional chain with corner-sharing grids propagating along the c-direction to lock the consecutive ligand struts of the (6,3) nets. This coordination polymer is porous to selectively adsorb CO₂.

Rheological properties of a hydrophobically associating polyacrylamide that exhibited stronger salt resistance compared with partially hydrolyzed polyacrylamide and the corresponding salt resistance mechanism was investigated in detail.

Assuming the surfactant can affect the formation of the core–shell structure of emulsion-electrospun fibres, two surfactants, Span 80 and SDS, were used separately in PLGA emulsions for electrospinning. Fibre samples collected along the fibre trajectory during emulsion electrospinning were studied and the respective fibre structural evolution processes are proposed.

Immobilization of WO₃- or TiO₂-supported PtRu nanoparticles onto the nanoporous platinized substrates leads to the formation of multifunctional electrocatalytic systems reactive towards oxidation of ethanol at fairly low potentials (<0.4 V vs RHE). Among the important issues are the presence of –OH groups at metal nanostructures, including oxidative removal of –CO adsorbates.

Chitosan is fluorescent for bio-imaging with low cytotoxicity due to the reaction with carbon dioxide. This paper investigates the photoluminescent behaviours of chitosan. Photoluminescence can be observed from aqueous solution of chitosan, and CO₂ treatment can improve the intensity of photoluminescence.

The micro-arrays of ZnSe nanospheres on a self-assembled sacrificial polystyrene mask showed excellent structural, morphological, and optical properties and demonstrated its usage in photovoltaic devices as an improved superior antireflective coating, with the reflectance decreased to nearly half of that of the ZnSe nanospheres fabricated on Au- and SU-8-coated Si substrates in the range of 300–800 nm.

Paper-based laboratory-on-a-chip has become a focusing issue for point of care test. So far, several platforms had been demonstrated, but are limited to chemical tests. The chip here combined reverse transcription loop-mediated isothermal DNA amplification (RT-LAMP) and colorimetric DNA detection, allowing effective assay of virus at a low cost.

Predicting pK_a is important in many areas of science, including chemical synthesis, structural biology, and the development of drug and functional materials. Computational chemistry provides a complementary alternative to experiment for estimating the pK_as of species ranging from small monoprotic acids, to larger and conformationally flexible polyprotic acids.

A short and expedient synthesis of three natural products from Leonurus japonicus is presented, along with their application as hepatoprotective agents.

Berberine–INF55 hybrids are a promising class of antibacterials that link berberine together with the NorA multidrug resistance pump inhibitor INF55. Parallel experiments comparing the activities of three different hybrids and their corresponding berberine–INF55 combinations showed that the hybrids and combinations do not exert antibacterial effects through the same mechanisms.

A model for the homogeneous Cr-PNP ethylene trimerisation and tetramerisation catalyst system has been studied theoretically, with the aim of identifying suitable DFT methods for treatment of this catalyst, and evaluating the likely oxidation and spin states of the active species.

Three series of new anthranilic diamide derivatives containing sulfide, N-cyanomethylsulfilimine, and N-cyanomethylsulfoximine moieties were designed and synthesized by coupling the active substructures of anthranilic diamides and sulfoxaflor. Bioassay results indicated that most of the synthesized compounds possessed good insecticidal activities against Mythimna separata and Plutella xylostella when compared with the positive control cyantraniliprole.

Self-assembly of three flexible bis(pyridyl) molecules with different inorganic acids (HPF₆, HClO₄, and HNO₃) leads to the formation of eight salts, which exhibit diverse architectures involving hydrogen bonding and anion–π interactions.

An efficient one-pot synthesis procedure of 2-imidazolines from aldehydes and ethylenediamine using molecular iodine and potassium carbonate in absolute ethanol at 25–30°C under ultrasound irradiation is described. The synthetic strategy has several advantages: mild conditions, low costs, readily available catalyst, short reaction times, and good-to-excellent yields.

The theoretical geometries, electronic structures, emission properties, and radiative decay rate constants (k_r) of four Pt complexes were investigated. The variation in charge transfer properties induced by the conjugation-extended methylimidazole group and the k_r results revealed that designed complex D is a more efficient blue phosphorescence material with a 497 nm emission.

Gelatin-functionalised graphene nanosheets (gelatin-GNS) with good biocompatibility were successfully synthesised using gelatin as a reductant. The gelatin-GNS adsorbed methotrexate (MTX) via strong π–π stacking interaction, exhibiting a high MTX drug loading capacity and excellent ability for controlled drug release. The pH-dependent release behaviour of MTX from MTX@gelatin-GNS showed that the release amount under acid conditions was much higher than that under neutral conditions, indicating a gelatin-mediated sustained release process.