Copper(I) Complexes of N-thiophosphorylated Bis-thiourea [CH2NHC(S)NHP(S)(OiPr)2]2 and Phosphines (PPh3, Ph2P(CH2)1–3PPh2, Ph2P(C5H4FeC5H4)PPh2): Versatile Structures and Luminescence

Reaction of the potassium solution of [CH2NHC(S)NHP(S)(OiPr)2]2 (H2L) with [Cu(PPh3)3I] or a mixture of CuI and Ph2P(CH2)1–3PPh2 or Ph2P(C5H4FeC5H4)PPh2 in aqueous EtOH/CH2Cl2 leads to binuclear [Cu2(PPh3)2L] (1), [Cu2(Ph2PCH2PPh2)L] (2), [Cu2{Ph2P(CH2)2PPh2}2L] (3), [Cu2{Ph2P(CH2)3PPh2}2L] (4) or [Cu2{Ph2P(C5H4FeC5H4)PPh2}2L] (5) complexes. The structures of these compounds were investigated by IR, 1H and 31P{1H} NMR spectroscopy; their compositions were examined by microanalysis. The luminescent properties of complexes 1–5 in the solid state are reported

Copper(I) Complexes of N-thiophosphorylated Bis-thiourea [CH2NHC(S)NHP(S)(OiPr)2]2 and Phosphines (PPh3, Ph2P(CH2)1–3PPh2, Ph2P(C5H4FeC5H4)PPh2): Versatile Structures and Luminescence

Reaction of the potassium solution of [CH2NHC(S)NHP(S)(OiPr)2]2 (H2L) with [Cu(PPh3)3I] or a mixture of CuI and Ph2P(CH2)1–3PPh2 or Ph2P(C5H4FeC5H4)PPh2 in aqueous EtOH/CH2Cl2 leads to binuclear [Cu2(PPh3)2L] (1), [Cu2(Ph2PCH2PPh2)L] (2), [Cu2{Ph2P(CH2)2PPh2}2L] (3), [Cu2{Ph2P(CH2)3PPh2}2L] (4) or [Cu2{Ph2P(C5H4FeC5H4)PPh2}2L] (5) complexes. The structures of these compounds were investigated by IR, 1H and 31P{1H} NMR spectroscopy; their compositions were examined by microanalysis. The luminescent properties of complexes 1–5 in the solid state are reported

Metal ion influences distortion of the ligand in the structure of [M{2−MeO(O)CC6H4NHC(S)NP(S)(OiPr)2}2](M=ZnII,CdII)[M\{2-MeO(O)CC_6H_4NHC(S)NP(S)(OiPr)_2\}_2] (M = Zn^{II}, Cd^{II}) complexes : a driving force for intermolecular aggregation

Reaction of the in situ deprotonated N-thiophosphorylated thiourea $2-MeO(O)CC_6H_4NHC(S)NHP(S)(OiPr)_2 (HL)$ with $MCl_2 (M = Zn^{II}, Cd^{II})$ in aqueous ethanol leads to complexes of the formula $[ML_2]$. Both compounds crystallise in the triclinic space group P[1 with combining macron] with Z = 2 and the metal cations are found in a tetrahedral S_2S′_2 coordination environment formed by the C–S and P–S sulfur atoms. The crystal structures reveal intramolecular N–H⋯O[double bond, length as m-dash]C hydrogen bonds formed within the $2-MeO(O)CC_6H_4NH$ fragments. Both structures are further stabilised by intermolecular π⋯π stacking interactions, which are more efficient in $[CdL_2]$. Here, a pronounced dimeric intermolecular aggregate is observed which goes along with a pronounced distortion of the chelate [(S)CNP(S)]− backbone of the ligand upon coordination to $Cd^{II}$ as well as a significantly distorted coordination tetrahedron $CdS_2S′_2$. The aggregation is also reflected in the positive electrospray ionisation (ESI) mass spectrum of the CdII complex, which exhibits peaks for the dimeric cations $[Cd_2L_3]+$, $[Cd_2L_4 + H]+$ and $[Cd_2L_4 + Na]+$, while for the ZnII analogue only monomeric species were observed. Quantum chemical ETS-NOCV (ADF) calculations confirm the higher stability of dimers in $[CdL_2]$ compared with $[ZnL_2]$. The π⋯π stacking interactions are prodominantly due to dispersion contributions, though the electrostatic and orbital interaction components are also important. QTAIM (ADF) type calculations additionally quantify the covalent and non-covalent interactions in the momomers

4-Bromo-N-(diisopropoxyphosphor­yl)benzamide

In the title compound, C13H19BrNO4P, the crystal structure is stabilized by inter­molecular N—H⋯O hydrogen bonds between the phosphoryl O atom and the amide N atom which link the mol­ecules into centrosymmetric dimers. These dimers are further packed into stacks along the c axis by inter­molecular C—H⋯O and C—H⋯π inter­actions

Anion-driven tetrel bond-induced engineering of lead(II) architectures with N′-(1-(2-pyridyl)ethylidene)nicotinohydrazide : experimental and theoretical findings

The evaluation of N′-(1-(2-pyridyl)ethylidene)nicotinohydrazide (HL) as a linker for the PbII tagged extended structures is described. The reaction of Pb(ClO4)2 or Pb(OAc)2 with HL in MeOH at 60 °C and room temperature, respectively, leads to heteroleptic complexes {[PbL]ClO4}n·nH2O and [PbL(OAc)]2, while the same reaction of Pb(ClO4)2 with HL at 60 °C in the presence of two equivalents of NaOAc or NaNO2 leads to heteroleptic complexes {[Pb(HL)(OAc)]ClO4}n and [PbL(NO2)]n, respectively. Using Pb(NO3)2 as a source of PbII in the same reaction with HL and two equivalents of NaN3 or NaNCS at room temperature yields [PbLN3]n and [Pb2(HL)2(NO3)2(NCS)2], respectively. The room temperature reaction of Pb(NO3)2 with HL in the presence of two equivalents of NaClO4 leads to the transformation of the parent ligand to its perchlorate salt [H2L]ClO4. In all the obtained PbII structures, HL or its deprotonated form L acts both as a chelating and a bridging ligand. The nature of the inorganic anion also influences the final structure. In all complexes the PbII center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151° to 232°. The sterically available PbII ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes. As a result of tetrel bonding, the structures of all the six compounds can be extended to a higher dimensional framework, which is further stabilized by π⋯π stacking interactions between the aromatic rings. The DFT based charge and energy decomposition (ETS-NOCV) calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures

Single-molecule magnetism arising from cobalt(II) nodes of a crystalline sponge

The remarkable Metal-Organic Framework (MOF), {[(Co(NCS)(2))(3)(kappa(3)-TPT)(4)]center dot a(H2O)center dot b(MeOH)}(n) (1), which is used in the revolutionary crystalline sponge method, displays characteristic Single-Molecule Magnet (SMM) behaviour under applied static fields. We report the subtle effects of changes in the coordination environment of the Co-II ions in 1, leading to drastically different magnetic behaviors of two additional related compounds, {[(Co(NCS)(2))(3)(kappa(0-3)-TPT)(4)]center dot c(H2O)}(n) (2) and {[(Co(NCS)(2)(H2O)(0.65)(MeOH)(0.35))(3)(kappa(3)-TPT)(2)]center dot 2.4(H2O)}(n) (3). Magnetic measurements reveal unquenched first order orbital angular momentum, leading to significant magnetic anisotropy in all compounds, which was corroborated through CASSCF-type calculations. Notably, the crystalline sponge is the first example of a 3D network built from Co-II Single-Ion Magnets (SIMs) as nodes

Tetrel bonding and other non-covalent interactions assisted supramolecular aggregation in a new Pb(II) complex of an isonicotinohydrazide

A new supramolecular Pb(II) complex [PbL(NO2)]n was synthesized from Pb(NO3)2, N’-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide (HL) and NaNO2. [PbL(NO2)]n is constructed from discrete [PbL(NO2)] units with an almost ideal N2O3 square pyramidal coordination environment around Pb(II). The ligand L− is coordinated through the 2-pyridyl N-atom, one aza N-atom, and the carbonyl O-atom. The nitrite ligand binds in a κ2-O,O coordination mode through both O-atoms. The Pb(II) center exhibits a hemidirected coordination geometry with a pronounced coordination gap, which allows a close approach of two additional N-atoms arising from the N=C(O) N-atom of an adjacent molecule and from the 4-pyridyl N-atom from the another adjacent molecule, yielding a N4O3 coordination, constructed from two Pb–N and three Pb–O covalent bonds, and two Pb⋯N tetrel bonds. Dimeric units in the structure of [PbL(NO2)]n are formed by the Pb⋯N=C(O) tetrel bonds and intermolecular electrostatically enforced π+⋯π− stacking interactions between the 2- and 4-pyridyl rings and further stabilized by C–H⋯π intermolecular interactions, formed by one of the methyl H-atoms and the 4-pyridyl ring. These dimers are embedded in a 2D network representing a simplified uninodal 3-connected fes (Shubnikov plane net) topology defined by the point symbol (4∙82). The Hirshfeld surface analysis of [PbL(NO2)] revealed that the intermolecular H⋯X (X = H, C, N, O) contacts occupy an overwhelming majority of the molecular surface of the [PbL(NO2)] coordination unit. Furthermore, the structure is characterized by intermolecular C⋯C and C⋯N interactions, corresponding to the intermolecular π⋯π stacking interactions. Notably, intermolecular Pb⋯N and, most interestingly, Pb⋯H interactions are remarkable contributors to the molecular surface of [PbL(NO2)]. While the former contacts are due to the Pb⋯N tetrel bonds, the latter contacts are mainly due to the interaction with the methyl H-atoms in the π⋯π stacked [PbL(NO2)] molecules. Molecular electrostatic potential (MEP) surface calculations showed marked electrostatic contributions to both the Pb⋯N tetrel bonds and the dimer forming π+⋯π− stacking interactions. Quantum theory of atoms in molecules (QTAIM) analyses underlined the tetrel bonding character of the Pb⋯N interactions. The manifold non-covalent interactions found in this supramolecular assembly are the result of the proper combination of the polyfunctional multidentate pyridine-hydrazide ligand and the small nitrito auxiliary ligand

Structural versatility of the quasi-aromatic Möbius type zinc(II)-pseudohalide complexes : experimental and theoretical investigations

In this contribution we report for the first time fabrication, isolation, structural and theoretical characterization of the quasi-aromatic Mobius complexes [Zn(NCS)(2)L-I] (1), [Zn-2(mu(1,1)-N-3)(2)(L-I)(2)][ZnCl3(MeOH)](2)center dot 6MeOH (2) and [Zn(NCS)L-II](2)[Zn(NCS)(4)]center dot MeOH (3), constructed from 1,2-diphenyl-1,2-bis((phenyl(pyridin-2-yl)methylene)hydrazono)ethane (L-I) or benzilbis(acetylpyridin-2-yl)methylidenehydrazone (L-II), respectively, and ZnCl2 mixed with NH4NCS or NaN3. Structures 1-3 are dictated by both the bulkiness of the organic ligand and the nature of the inorganic counter ion. As evidenced from single crystal X-ray diffraction data species 1 has a neutral discrete heteroleptic mononuclear structure, whereas, complexes 2 and 3 exhibit a salt-like structure. Each structure contains a Zn-II atom chelated by one tetradentate twisted ligand L-I creating the unusual Mobius type topology. Theoretical investigations based on the EDDB method allowed us to determine that it constitutes the quasi-aromatic Mobius motif where a metal only induces the pi-delocalization solely within the ligand part: 2.44|e| in 3, 3.14|e| in 2 and 3.44|e| in 1. It is found, that the degree of quasi-aromatic pi-delocalization in the case of zinc species is significantly weaker (by similar to 50%) than the corresponding estimations for cadmium systems - it is associated with the Zn-N bonds being more polar than the related Cd-N connections. The ETS-NOCV showed, that the monomers in 1 are bonded primarily through London dispersion forces, whereas long-range electrostatic stabilization is crucial in 2 and 3. A number of non-covalent interactions are additionally identified in the lattices of 1-3

Lead(II) coordination polymers driven by pyridine-hydrazine donors : from anion-guided self-assembly to structural features

In this work, we report extensive experimental and theoretical investigations on a new series of PbII coordination polymers exhibiting extended supramolecular architectures, namely [Pb2(LI)(NCS)4]n (1), [Pb(HLII)I2]n (2), [Pb(LIII)I]n (3) and [Pb(HLIV)(NO3)2]n·nMeOH (4), which were self-assembled from different PbII salts and various pyridine-hydrazine based linkers, namely 1,2-bis(pyridin-3-ylmethylene)hydrazine (LI), (pyridin-4-ylmethylene)isonicotinohydrazide (HLII), 1-(pyridin-2-yl)ethylidenenicotinohydrazide (HLIII) and phenyl(pyridin-2-yl)methylenenicotinohydrazide (HLIV), respectively. It is recognized that the origin of self-assembling is fundamentally rooted in a dual donor (6s2/6p0 hybridized lone electron pair) and electrophilic behaviour of PbII. This allows production of extended topologies from a 1D polymeric chain in 4 through a 2D layer in 2 to the 3D frameworks in 1 and 3, predominantly due to the cooperative action of both covalent and non-covalent tetrel interactions of the overall type Pb-X (X = O, N, S, I). Counterintuitively, the latter, seemingly weak interactions, have appeared to be even stronger than the typical covalent bonds due to the presence of a bunch of supportive London dispersion dominated contacts: ππ, Lpπ, C-HO, C-HI, C-HH-C as well as more typical mainly electrostatically driven N-HO or N/O-HO hydrogen bonds. It is revealed that the constituting generally strong tetrel type Pb-X (X = O, N, S, I) bonds, though dominated by a classic Coulomb term, are therefore characterized by a very important London dispersion constituent, extremely strong relativistic effects and the two way dative-covalent Pb ↔ X electron charge delocalization contribution as revealed by the Extended Transition State Natural Orbital for Chemical Valence (ETS-NOCV) charge and energy decomposition scheme. It unravels that the pyridine-hydrazine linkers are also excellent London dispersion donors, and that together with the donor-acceptor properties of the heavy (relativistic) PbII atoms and nucleophilic counterions lead to extended self-assembling of 1-4

First evidence of thermo- and two-step photochromism of tris-anils

Seven N,N9,N99-tris(salicylidene)triamines of common formula N(CH2CH2NLCH–aryl) [aryl = 2-OH-C6H4 (1), 2-OH-(5-Cl)C6H3 (2), 2-OH-(5-Br)C6H3 (3), 2,5-(OH)2C6H3 (4), 2,4-(OH)2C6H3 (5), 2,3,4-(OH)3C6H2 (6) and 2-OH-C10H6 (7)] have been synthesized and characterized by elemental analysis, X-ray powder diffraction, NMR, diffuse reflectance, Raman and fluorescence spectroscopy. All the tris-anils are thermochromic. 4 exclusively displays photochromism upon irradiation at 365 nm with a unique two-step back thermal relaxation, with kinetic constants kI = 1.061025 s21 and kII = 4.061025 s21 for the first and second steps, respectively. The origin of the observed photochromism is due to a cis/trans-keto isomerization