Interactions of guanidinium with benzene-sulphonic, -phosphonic and -arsonic acids and several of their nitro-derivatives

Guanidinium Iodide-Modified PEDOT:PSS Hole Transport Layer for Improving the Performance of 2D Perovskite Solar Cells

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been widely used as a hole transporting layer (HTL) in two-dimensional (2D) Ruddlesden-Popper perovskite (RPP)-based solar cells (2D-PSCs) due to its simple preparation process and low cost. However, the devices based on PEDOT:PSS exhibit low efficiency and poor stability due to the number of buried interfacial defects, energy level mismatching, and corrosivity of the HTL. In this study, a guanidinium iodide (GAI)-modified PEDOT:PSS HTL was adopted to tune the crystallization of 2D RPPs, leading to the formation of 2D perovskite films with preferential crystal orientation, improved crystallinity, and suppressed defect density. The addition of GAI not only enhances the conductivity and intrinsic stability of PEDOT:PSS layers but also improves their energy level matching with those of 2D perovskite films. Upon GAI doping into PEDOT:PSS, the power conversion efficiency of 2D-PSCs increased from 13.11% to 16.04% and maintained 80% of its initial value under 65% relative humidity condition for 60 days. This work demonstrates a novel synergetic modification strategy and gives new insight into the underlying mechanism, which should lead to further improvements in the performance of 2D-PSCs and other optoelectronic devices based on 2D RPPs.

Different coordination geometries of lighter lanthanates driven by the symmetry of guanidines as charge compensators

Six and nine coordination geometries of lighter lanthanates have been successfully synthesized using a controlled process under oil-bath conditions.

Crystal structure and hydrogen bonding in the water-stabilized proton-transfer salt brucinium 4-amino-phenyl-arsonate tetra-hydrate

In the structure of the brucinium salt of 4-amino-phenyl-arsonic acid (p-arsanilic acid), systematically 2,3-dimeth-oxy-10-oxostrychnidinium 4-amino-phenyl-ar-son-ate tetra-hydrate, (C23H27N2O4)[As(C6H7N)O2(OH)]·4H2O, the brucinium cations form the characteristic undulating and overlapping head-to-tail layered brucine substructures packed along [010]. The arsanilate anions and the water mol-ecules of solvation are accommodated between the layers and are linked to them through a primary cation N-H⋯O(anion) hydrogen bond, as well as through water O-H⋯O hydrogen bonds to brucinium and arsanilate ions as well as bridging water O-atom acceptors, giving an overall three-dimensional network structure.

The three-dimensional hydrogen-bonded structures in the ammonium and sodium salt hydrates of 4-aminophenylarsonic acid

The structures of two hydrated salts of 4-aminophenylarsonic acid (p-arsanilic acid), namely ammonium 4-aminophenylarsonate monohydrate, NH4(+)·C6H7AsNO3(-)·H2O, (I), and the one-dimensional coordination polymer catena-poly[[(4-aminophenylarsonato-κO)diaquasodium]-μ-aqua], [Na(C6H7AsNO3)(H2O)3]n, (II), have been determined. In the structure of the ammonium salt, (I), the ammonium cations, arsonate anions and water molecules interact through inter-species N-H...O and arsonate and water O-H...O hydrogen bonds, giving the common two-dimensional layers lying parallel to (010). These layers are extended into three dimensions through bridging hydrogen-bonding interactions involving the para-amine group acting both as a donor and an acceptor. In the structure of the sodium salt, (II), the Na(+) cation is coordinated by five O-atom donors, one from a single monodentate arsonate ligand, two from monodentate water molecules and two from bridging water molecules, giving a very distorted square-pyramidal coordination environment. The water bridges generate one-dimensional chains extending along c and extensive interchain O-H...O and N-H...O hydrogen-bonding interactions link these chains, giving an overall three-dimensional structure. The two structures reported here are the first reported examples of salts of p-arsanilic acid.