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A straightforward synthesis of the tetradentate phospholane ligand 1 is reported. The 2 : 1 [M : L] reaction of 1 with [AuCl(tht)] (tht = tetrahydrothiophene) resulted in the 4 : 2 [M : L] supramolecular coordination complex 2 where two ligands 1 are bridging four gold(I) cations. The formation of 2 can be rationalised via a geometrical analysis of the ligand. The coordination mode of the gold atoms was evaluated based on a CSD search, revealing the geometrical changes for a transition from linear to trigonal planar coordination environment.

The cyclo-(P4tBu3) synthon [Li{cyclo-(P4tBu3)}(thf)(tmeda)] (1) (thf = tetrahydrofuran, tmeda = N,N,N′,N′-tetramethylethane-1,2-diamine) is readily accessible in a one-pot synthesis from P4 and LitBu. The use of 1 as a cyclo-(P4tBu3) building block enables the rational synthesis of cyclo-(P4tBu3)-containing oligophosphanes, namely {cyclo-(P4tBu3)}2 (2), {cyclo-(P4tBu3)}2PtBu (3) and {cyclo-(P4tBu3)}2CH2 (4), C3v-symmetric pnictaphosphanes E{cyclo-(P4tBu3)}3 (E = Bi, Sb, As; 5–7) as well as AsCl{cyclo-(P4tBu3)}2 (8). Compounds 5 and 6 represent the first neutral homoleptic bismuthane and stibane that contain only bonds to phosphorus. All new compounds were isolated in moderate to good yields and fully characterised. The 31P{1H} NMR spectral data of 1, 2, 4, and 8 have been determined by automated line-shape analysis.

A dynamic covalent chemistry approach was used for the stereoselective synthesis of 1,10-diaza-3,8,12,17-tetraphosphacyclooctadecanes via condensation reaction of 1,4-bis(organylphosphino)butane, formaldehyde, and primary amines. The obtained 18-membered P4N2 macrocycles were isolated in pure form as meso- (RPSPSPRP) or rac- (RPRPRPRP/SPSPSPSP) isomers. The structural features of the individual stereoisomers were revealed by NMR spectroscopy and X-ray structure analysis. All P4N2 macrocycles form square-planar nickel(II) complexes with the RPSPSPRP isomer only, in which the orientation of the lone pairs of electrons at phosphorus favors this coordination mode, independent of the initial configuration of the ligand, indicating the ability of the 18-membered P4N2 macrocycles to stereoisomerize in the course of the complexation.

New water-soluble copper(II) bis-N,O-chelate complexes [Cu(L2)2Cl2] (I), [Cu2(L1)2Cl4] (II), and [Cu(L1)2Cl]2[CuCl4] (III) (L1, L2 = pyridyl-containing phospholane oxides) were prepared from N,O-ligands. The complexes were characterized by physicochemical methods (mass spectrometry, IR spectroscopy, elemental analysis, and X-ray diffraction (CIF files CCDC nos. 1976723 (I), 1976724 (II), and 1974303 (III)). The physicochemical properties of the products were studied and the molecular and crystal structures were established. The cytotoxicity against M-HeLa cancer cell lines and Chang liver normal cell lines was determined for the binuclear complex [Cu2(L1)2Cl4].

In a 2:2 reaction with silver(I) chloride or bromide, 1,5‐bis(1‐phospholano)pentane (1a) afforded frame‐like macrocyclic structures, with intra‐ (2, Cl) or intermolecular (3, Br) halido bridges. In contrast, 1,7‐bis(1‐phospholano)heptane (1b) formed coordination polymers 4a (Cl) and 4b (Br) with bridging bis‐phospholane and halido ligands. A unique paddle wheel‐type metallacryptand structure 5 was obtained from 1a and silver(I) bromide in a 2:3 reaction (M:L). All complexes were fully characterized by NMR, IR spectroscopy, mass spectrometry, and X‐ray crystallography., John Wiley & Sons, Ltd.

Introduction of a bis(isopropylidene)-protected galactopyranosyl moiety in s-triazine-based boron-rich carboxylic acids and amines results in soluble and suitable coupling partners for tumour-selective biomolecules with applications as selective agents for boron neutron capture therapy (BNCT). Bearing either a carboxylic acid or primary amine as a functional group, these compounds are highly versatile and thus largely extend the possible coupling strategies with suitable biomolecules. Modification of the gastrin-releasing peptide receptor (GRPR) selective agonist [D-Phe6, β-Ala11, Ala13, Nle14]Bn(6–14) with the carboxylic acid derivative yielded a bioconjugate with an optimal receptor activation and internalisation profile. This demonstrates the great potential of this approach for the development of novel boron delivery agents.

A family of helical dinuclear copper(I) pyridylphospholane complexes [Cu2L3X]X (X = BF4−, Cl− and Br−) was prepared. The family includes the first examples of this type of complex based on copper(I) chloride and copper(I) bromide. The two isomers typical of this class of compounds, namely head-to-head and head-to-tail complexes, were studied in solution by spectroscopic and optical methods, and in the solid state by X-ray diffraction. Furthermore, the solid-state luminescence of the complexes at different temperatures was studied, and the results were interpreted using quantum-chemical calculations. It was shown that the luminescence of the complexes is attributed to the 3(M + X)LCT transitions.

Stereoselective synthesis of the first representatives of 1,12-diaza-3,10,14,21-tetraphosphacyclodocosanes was achieved via the Mannich-type condensation of 1,6-bis(phenylphosphino)hexane, formaldehyde and primary amines. Due to covalent self-assembly, individual RPSPSPRP isomer was isolated from a dynamic system containing all possible stereoisomers and a number of by-products.

Deboronation of a carborane-substituted diphosphetane 2 in toluene yielded the first nido-carboranyldiphosphetane 1. The P-P bond in 1 can be broken via dismutation reactions with diaryl dichalcogenides yielding nido-carboranyl bis-phosphanes that were not accessible via established synthetic protocols. Additionally, transition metal complexes of 1 could be isolated including one coordination polymer. Notably, when the deboronation of 2 is carried out in ethanol, unprecedented nido-carborane-substituted secondary bis-phosphane monoxides (3, 4) are obtained. These compounds are interesting starting materials for further reactivity studies due to their P-H bonds. Experimental findings are supported by DFT calculations including the calculation of reaction mechanisms and NMR spectroscopic parameters.

Group 6 metal (Cr, Mo, W) carbonyl complexes react with cyclo-(P5Ph5) to afford the phosphorus-rich complexes [Cr(CO)5{cyclo-(P5Ph5)-κP 1}] (1), [{Cr(CO)5}2{μ-cyclo-(P5Ph5)-κP 1,P 3}] (2), [M(CO)4{cyclo-(P5Ph5)-κP 1,P 3}] (with M=Cr (3), Mo (4), W (exo-5, endo -5)) depending on the reaction conditions. Complexes 1–5 were characterised by 31P{1H} NMR and IR spectroscopy, elemental analysis, and X-ray crystallography. The cyclopentaphosphane remains intact and acts as monodentate (1), bridging (2) or bidentate (3–5) ligand. Compounds exo-5 and endo -5 are configurational isomers and essentially differ in the orientations adopted by the phenyl rings attached to the uncoordinated phosphorus atoms. The 31P{1H} NMR spectra show five multiplets for an ABCDE spin system. Theoretical calculations showed that exo-5 and endo-5 are practically isoenergetic, which is in good agreement with the observed equilibrium in solution between exo-5 and endo-5. The thermal properties of the complexes have also been evaluated.

5-Lipoxygenase converts arachidonic acid into leukotrienes, which are involved in inflammation and angiogenesis. The introduction of carboranes can improve the pharmacokinetic behavior of metabolically less stable pharmaceutics. Herein we report the syntheses of several carborane-based inhibitors of the 5-lipoxygenase pathway. The isosteric replacement of phenyl rings by carboranes leads to improved cytotoxicity toward several melanoma and colon cancer cell lines. For the colon cancer cell line HCT116, the co-inhibition of heat shock protein 90 was observed.

In contrast to their mostly unstable isolobal carbon counterparts, oligophosphanide anions, such as M(cyclo-P5 t Bu4) (M=Li, Na) and M2(P4R4) [M=Na, K; R=Ph, t Bu, 2,4,6-Me3C6H2 (Mes)], have unique features, depending on their composition and structure, and are highly suitable building blocks for the synthesis of phosphorus-rich metal compounds. However, alkali metal oligophosphanediides are highly reactive and highly reducing, and a major problem is their tendency for disproportionation in reactions with electrophiles. This, however, can also give rise to a fascinating chemistry of making and breaking of P–P bonds. On the other hand, neutral cyclooligophosphines, such as cyclo-(P5Ph5), are suitable stable ligands for the formation of phosphorus-rich metal complexes.

The development of novel, tumor-selective and boron-rich compounds as potential agents for use in boron neutron capture therapy (BNCT) represents a very important field in cancer treatment by radiation therapy. Here, we report the design and synthesis of two promising compounds that combine meta-carborane, a water-soluble monosaccharide and a linking unit, namely glycine or ethylenediamine, for facile coupling with various tumor-selective biomolecules bearing a free amino or carboxylic acid group. In this work, coupling experiments with two selected biomolecules, a coumarin derivative and folic acid, were included. The task of every component in this approach was carefully chosen: the carborane moiety supplies ten boron atoms, which is a tenfold increase in boron content compared to the l-boronophenylalanine (l-BPA) presently used in BNCT, the sugar moiety compensates for the hydrophobic character of the carborane, the linking unit, depending on the chosen biomolecule, acts as the connection between the tumor-selective component and the boron-rich moiety, and the respective tumor-selective biomolecule provides the necessary selectivity. This approach makes it possible to develop a modular and feasible strategy for the synthesis of readily obtainable boron-rich agents with optimized properties for potential applications in BNCT.

(R)-[Ru(eta(6)-p-(MeC6H4Pr)-Pr-i)Cl-2{Ph2PNHCH(CH3)(C6H4-4-F)}] (1) and cis-(R,R)-[PtCl2{Ph2PNHCH(CH3)(C6H4-4-F)}(2)] (2) have been obtained by the reaction of the chiral aminophosphine (R)-Ph2PNHCH(CH3)(C6H4-4-F) with [{RuCl(mu-Cl)(eta(6)-p-(MeC6H4Pr)-Pr-i)}(2)] or [PtCl2(cod)] (cod = cycloocta-1,5-diene). Both complexes were characterized by physico-chemical and spectroscopic methods. Compound 1 was also characterized by X-ray crystallography. The antitumor potential of both compounds was investigated by using the crystal violet antiproliferation assay. Complexes 1 and 2 were found to inhibit the growth of three human cancer cell lines, whereby the Ru complex was considerably more potent than the Pt complex, with IC50 values between 1 and 3 and 12-15 mu M, respectively, but still less potent than cisplatin in the same three cell lines.

The 1,3-dipolar cycloaddition of chiral 1-alkyl-1,2-diphosphacyclopenta-2,4-dienes ((1-(−)-menthyl)oxymethyl-1,2-diphosphole and 1-(+)-neomenthyl-1,2-diphosphole) with diphenyldiazomethane leads to novel P-chiral bicyclic phosphiranes having six chiral centers. The degree of diastereoselectivity depends on the substituent at phosphorus, and dramatically increases in the case of (+)-neomenthyl group (de up to 71%). DFT calculations indicate that the cycloaddition is thermodynamically controlled.

A one-dimensional {[Zn(L)(DMF)2]}n (1) and a three-dimensional {[Cd(L)(DMF)]·DMF}n (2) coordination polymer based on the novel anthracene derivative H2L (H2L = 4,4'-(9,10-anthracenediyl)dicinnamic acid) were obtained by solvothermal synthesis and charaterised by single-crystal and powder X-ray diffraction, thermogravimetry, and infrared spectroscopy. The anthracene derivative H2L and coordination polymers 1 and 2 were used to modify a glassy carbon electrode and as such served as an active material for detection of H2O2. Cyclic voltammograms in the potential range from 0 to -0.5 V revealed concentration-dependent cathodic current in all three cases with a lower detection limit of 200 μM. The electrode modified with compound 2 showed the best performance towards hydrogen peroxide detection. The results suggest that the development of electrodes modified with inorganic polymers based on highly conjugated ligands can serve as potential electrocatalytic materials.

Three coordination polymers, 1∞[Cu3L2(NO3)]NO3·2MeOH·2H2O (1), 1∞[Cu3L2(N3)]CH3COO (2) and 1∞[Cu3L2(H2O)](ClO4)2 (3), based on the Schiff base H2L (H2L = N,N’-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine) have been synthesized and characterized. X-ray single-crystal analysis shows that compounds 1 and 2 are isostructural and crystallize in a non-centrosymmetric space group, P212121, while complex 3 crystallizes in a monoclinic system, space group P21/c. Compounds 1–3 consist of trinuclear complex entities, {Cu3L2}2+, connected via different bridges, nitrato (1), azido (2) and phenoxido (3), depending on the nature of the counterion. The cryomagnetic measurements reveal weak ferromagnetic interactions between the copper(II) ions bridged by the nitrato ligands in 1 (J = +1.026 cm−1, H = -JS1S2) and a weak antiferromagnetic coupling between the copper(II) ions connected by azido groups in 2 (J = -0.295 cm−1). The exchange interaction between the copper(II) ions connected by two phenoxido groups is antiferromagnetic, J = −12.780 cm−1.

Manganese(III)-salen complexes have been reported as superoxide dismutase mimics (mSOD) that can scavenge superoxide anion radicals. They are mononuclear complexes with a variety of salen ligands. Here, two new multinuclear manganese(III)-salen complexes with 4,4′-bipyridine (4,4′-bpy) as bridging ligand and ClO4− as axial ligand or PF6− as counter anion, respectively, are reported. The dimeric complex [{Mn(ClO4)(salen)}2(μ-4,4′-bpy)] (1) was obtained from [MnCl(salen)]·2H2O and 4,4′-bipyridine which followed by addition of NaClO4. While the polymeric complex {[Mn(salen)(4,4′-bpy)]PF6}n (2) was prepared by the same procedure of 1, followed by addition of KPF6 replacing NaClO4. Compounds 1 and 2 were characterized by elemental analysis, conductometry, infrared spectroscopy, electrospray-ionization mass spectrometry, and room temperature/variable temperature magnetic susceptibility measurements. The crystal structures of compounds 1 and 2 were determined by single crystal X-ray crystallography. Furthermore, in indirect SOD tests using riboflavin photoreduction, the polymeric compound 2 shows the slightly higher SOD activity with an IC50 of 1.6 ± 0.2 µM than the dimeric compounds 1 with an IC50 of 2.0 ± 0.3 µM.

3,4,5-Triphenyl-1-(+)-neomenthyl-1,2-diphosphole and 3,5-di-(tert-butyl)-1-(+)-neomenthyl-1,2,4-triphosphole were obtained by alkylation of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide and 3,5-di-(tert-butyl)-1,2,4-triphosphacyclopentadienide with (−)-menthyl tosylate in 70% yield. These P-heterocycles react with [W(CO)5(THF)] to give the 1:1 complexes with high regioselectivity - tungsten is coordinated exclusively by the dicoordinated phosphorus atom P2. Complex formation causes quite pronounced charge redistribution within the heterocyclic moieties and has also a rather pronounced impact on the frontier molecular orbitals of the ligands. This is reflected in a strong bathochromic shift of the lowest-energy absorption band and in a change of the corresponding electronic transition from a π-π* transition for the ligands to a metal-to-ligand charge transfer transition (MLCT) for the tungsten complexes.

Four new complexes, [Cu 9 L 6 ( µ 3 -ClO 4 ) 2 ](ClO 4 ) 4 ·4CHCl 3 1 , [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O 2 , [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 3 and [Cu 2 L(CH 3 COO) 2 ] 4 , where H 2 L stands for the Schiff base N , N ′-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine, were obtained and structurally characterized. Compounds 1 , 2 and 3 contain the Cu 3 L 2 2+ entities in which L 2− acts in an unsymmetrical mode with N 3 O donor set wrapped around marginal copper(II) and with the remained NO sets bound to the central copper ion. The marginal copper(II) ions are in distorted square pyramidal environment, whereas that of the central one is square planar. In 1 , the peripheral copper(II) ions (Cu1) are disposed linearly with a two-fold axis passing through the central Cu2 and with the Cu1⋯Cu2 and Cu2⋯Cu1′ distances of 6.755 A. The linear trinuclear units are bridged by a rare µ 3 -1,2,3 perchlorate ligand thus describing a 2D network. In [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O, the Cu 3 L 2 2+ unit is capped by two water molecules. Here, due to the intramolecular hydrogen bonds, the metal ions are disposed in the corner of a triangle with the Cu1⋯Cu2, Cu1⋯Cu3 and Cu2⋯Cu3 distances of 5.976, 5.314 and 5.760 Ǻ, respectively. In [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 , two Cu 3 L 2 2+ units are bridged by two azido groups thus forming a macrocycle of six copper(II) ions. In [Cu 2 L(CH 3 COO) 2 ], L 2− acts as a symmetrical binucleatig ligand through the two N 2 O sets disposed on each side of the piperazine ring and pointed away in opposite directions. The square pyramidal environment of copper is achieved by chelate acetato co-ligand.

1,3,5-Triphospha-1,4-pentadiene-2,4-diamine reacts with [M(CO)4L] (M = Mo, L = nbd (norbornadiene); M = W, L = 2 CH3CN) to give the chelate complexes [M(CO)4(PMes{C(NHCy)PMes}2-κ P1 ,P3)]. In contrast, an unusual intramolecular rearrangement occurred with [Cu(CH3CN)4]PF6 leading to the dimeric copper(I) complex [Cu(CNCy){PHMesPMesC(NHCy)PMes-κ P1 ,P3}]2(PF6)2. The mechanism of the rearrangement was supported by quantum-mechanical calculations. The transition-metal complexes were characterized by multinuclear NMR spectroscopy, mass spectrometry, infrared spectroscopy, and X-ray crystallography.

Novel 1,9-diaza-3,7,11,15-tetraphosphacyclohexadecanes with alkyl, arylalkyl, or heteroarylalkyl substituents at the endocyclic nitrogen atoms were synthesized by condensation of 1,3-bis(phenylphosphino)propane, formaldehyde, and primary amines. The reactions are stereoselective and result in the isomer with the RSSR configuration of the phosphorus atoms as the major product. The 16-membered tetrakis(phosphine) ligands form stable neutral tetranuclear complexes with gold(I). In these complexes, the 16-membered cyclic ligands retain their free-state conformations and the configuration of the chiral phosphorus atoms.

Chiral 1,9-diaza-3,7,11,15-tetraphosphacyclohexadecanes were stereoselectively synthesized as pure RPSPSPRP isomers via a one-pot Mannich-type condensation reaction of 1,3-bis(arylphosphino)propane, formaldehyde and optically active, as well as racemic, primary amines. An unprecedented intermolecular exchange of endocyclic amino fragments of 1,9-diaza-3,7,11,15-tetraphosphacyclohexadecanes was observed. The lability of the P–CH2–N fragment in macrocyclic aminomethylphosphines is the reason of the stereoisomerization, formation of products with medium-sized cycles as well as the exchange of endocyclic amino fragments. The mechanism of these transformations involving the formation of a methylenephosphonium intermediate and further intra- and intermolecular nucleophilic substitution is discussed.

Direct conversion of elemental white phosphorus (P4) to organophosphorus compounds is an attractive and challenging goal in sustainable phosphorus chemistry. We report here the one-pot reaction of P4, sodium metal and (1,2,3-triphenylcyclopropenyl)phosphonium bromides 1a,b to give exclusively sodium 3,4,5-triphenyl-1,2-diphospholide 2. An electrochemical method for following the conversion of 1,2,3-triphenylcyclopropenylphosphonium bromides to sodium 3,4,5-triphenyl-1,2-diphospholide is also presented.

The nitrogen atom in cyclic hetero-oligophosphane cyclo-P4Mes4C(NCy) (1) can be protonated with HCl or HBF4. The resulting cation was isolated as the BF4-, AlCl4- and GaCl4- salts and characterised by NMR spectroscopy, mass spectrometry and X-ray crystallography. According to quantum mechanical calculations, the basicity of compound 1 is comparable to that of methyl-substituted monophospha(III)guanidine. The pKα value of 1 was also determined experimentally with indicator bases.

Two bis-phospholane copper(I) metallamacrocycles were selectively synthesized starting from the same two building blocks, namely, ligand 1 and [Cu(NCCH3)4]BF4. Reaction conditions (ligand:metal (L:M) ratio and dilution) can be tuned to obtain either a paddle-wheel- (2, L:M = 3:2) or box-type complex (3, L:M = 8:4). Their structures were unequivocally determined by X-ray crystallography. The solution 31P{1H} NMR spectrum of complex 2 consists of a broad signal, as is common for such complexes, whereas complex 3 shows splitting of the 31P{1H} NMR signal into a pseudoquartet due to 63,65Cu–31P coupling, a rare occurrence exhibited only by highly symmetrical copper(I) phosphine complexes.

The reaction of cyclo-P4 Mes4 C(NCy) (1) with two equivalents of [AuCl(tht)] (tht=tetrahydrothiophene) resulted in the formation of unusual sixteen-membered Au-P macrocycle 2. This macrocycle contains diphospha(III)guanidinate as a coordinating ligand, which is formed by P-P bond cleavage of 1. Macrocycle 2 was characterized by multinuclear NMR spectroscopy, mass spectrometry and X-ray crystallography.

A series of mono-, di- and tetranuclear copper(I) complexes with macrocyclic 14-, 16-, 18- and 20-membered tetrakis-phosphine ligands (P4N2) was obtained and fully characterized including single crystal X-ray diffraction. The 14-membered P4N2 macrocycles form very stable cationic mononuclear tetraphospha-coordinated copper(I) complexes, whereas their higher 16-, 18- and 20-membered homologues give neutral dinuclear [Cu2I2L] complexes under the same conditions. An unusual tetranuclear complex with two three- and two four-coordinated copper(I) atoms was obtained from 16-PMes 4NCH2CH2Py-2 2 and copper(I) iodide. This is the first example of N-coordination of cyclic aminomethylphosphines towards “soft” copper(I).

A luminescent zinc-based metal-organic framework (MOF; 1) was synthesized from a highly conjugated tridentate ligand, 1,3,5-tris[(1E)-2′-(4′′-benzoic acid)vinyl]benzene. X-ray single crystal analysis reveals the organization of 1 in a three-dimensional porous framework. Thermogravimetric analysis shows that 1 has a good thermal stability, and resists decomposition up to 420 °C. The removal of the solvent molecules from the cavities leads to a temporary loss of crystallinity, which can be regained by heating the MOF in diethylformamide, the solvent used for the synthesis, as shown by powder X-ray diffraction. In addition, 1 shows luminescent features influenced by the chemical environment, making it suitable as optical sensor. Detection of methanol with a turn-on effect was possible in low concentration in mixtures with water (50 μL/3 mL and 10 μL/3 mL) and as vapor.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most common way of treating inflammatory disorders. Their widespread use helped reveal their other modes of action as pharmaceuticals, such as a profound effect on various cancers. Celecoxib has proven to be a very prominent member of this group with cytostatic activities. On the other hand, the highly dynamic field of drug design is constantly searching for new ways of modifying known structures to obtain more powerful and less harmful drugs. A very interesting development is the implementation of carboranes in pharmacologically active structures, mostly as phenyl mimetics. Herein we report the synthesis of three carborane-containing derivatives of the COX-2-selective NSAID celecoxib. The new compounds proved to have promising cytostatic potential against various melanoma and colorectal adenocarcinoma cell lines. Inhibited proliferation accompanied by caspase-independent apoptotic cell death was found to be the main cause of decreased cell viability upon treatment with the most efficient celecoxib analogue, 3 b (4-[5-(1,7-dicarba-closo-dodecaboranyl)-3-trifluoromethyl-1H-pyrazol-1-yl]-1-methylsulfonylbenzene).

Three cadmium(II) complexes formulated as [Cd3L(CH3COO)4]·H2O (1), [Cd2L(NO3)2]·CHCl3 (2) and [Cd5L2(CH3COO)6] (3) have been obtained by reacting appropriate CdII salts with N,N’-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine (H2L). X-ray single-crystal analysis shows that compounds 1-3 crystallize in the triclinic space group P 1 ¯ and consist of CdII ions with distorted octahedral geometry, connected to form trinuclear (1) and binuclear (2) units and a combination of both in 3. A piperazine moiety, in chair conformation, acts as a bridge between these polynuclear units to form 1D chains. Blue luminescence in the range of 460−490 nm was observed upon excitation at 345 nm in the solid state. The investigation of the degradation of the dye Congo Red (CR) under visible light, revealed very good photocatalytic activity of the obtained coordination polymers. The photocatalytic process follows first-order reaction kinetics.

An efficient way to obtain pure diastereomeric mixtures of C-chiral, P-chiral, planar-chiral ferrocenylphosphanes is demonstrated by ortho-lithiation of enantiomerically pure (SC)-N,N-dimethyl-1-ferrocenylethylamine (Ugi's amine) and reaction with RPX2 [X = Cl, Br; R = tBu, 2,4,6-Me3C6H2 (Mes)]. Four secondary ferrocenylphosphanes [Fe(C5H5)(1-PHR-2-CHR'NMe2-C5H3)] (R' = H, R = tBu (1); R' = H, R = Mes (2); R' = CH3, R = tBu (3); R' = Me, R = Mes (4) were synthesised and characterised. Pure diastereomeric mixtures of 1 and 2, a mixture of the pure major diastereomers of 4 and diastereomerically pure 3 were obtained by column chromatography under nitrogen atmosphere. The formation of amine-borane or phosphane-borane adducts was studied by 11B and 31P NMR spectroscopy. A theoretical study was performed to understand the tendency of 1-4 toward borane adduct formation.

A series of Ru(II) arene complexes of mono- and bidentate N-donor ligands with carboxyl or ester groups and chlorido ancillary ligands were synthesised and structurally characterised. The complexes have a distorted tetrahedral piano-stool geometry. The binding interaction was studied with calf thymus DNA (CT-DNA) by absorption titration, viscosity measurement, thermal melting, circular dichroism, ethidium bromide displacement assay and DNA cleavage of plasmid DNA (pBR322), investigated by gel electrophoresis. The dichlorido complexes bind covalently to DNA in the dark, similar to cisplatin, while the monochlorido complexes bind covalently on irradiation, similar to cisplatin analogues. The compounds are selectively cytotoxic against several tumour cell lines and show specific nonlinear correlation between dose and activity. This phenomenon is closely related to their potential to act preferentially as inhibitors of cell division.

Ruthenium-based complexes have received much interest as potential metallodrugs. In this work, four RuII complexes bearing a dicarbollide moiety, a carbonyl ligand, and a phenanthroline-based ligand were synthesized and characterized, including single crystal diffraction analysis of compounds 2, 4, and 5 and an observed side product SP1. Complexes 2&ndash, 5 are air and moisture stable under ambient conditions. They show excellent solubility in organic solvents, but low solubility in water.

New chiral 3,4,5-triphenyl-1-((1R,2S,5R)-menthyl)oxymethyl-1,2-diphosphole (1) was prepared by reaction of sodium 1,2-diphospholide with chloromethyl (1R,2S,5R)-(−)-menthyl ether. The extent of asymmetric induction in the [4 + 2] cycloaddition reaction of chiral 1 with maleic anhydride was studied and the absolute configuration of the [4 + 2] cycloadducts determined by X-ray structure analysis.

Three water-soluble tris-heteroleptic ruthenium(II) polypyridyl complexes [Ru(bpy)(phen)(bpg)]2+ (1), [Ru(bpy)(dppz)(bpg)]2+ (2), and [Ru(phen)(dppz)(bpg)]2+ (3) (where bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, dppz = dipyrido[3,2-a:2′,3′-c] phenazine, bpg = 4b,5,7,7a-tetrahydro-4b,7a-epiminomethanoimino-6H-imidazo[4,5-f] [1,10] phenanthroline-6,13-dione) have been synthesized and characterized. Molecular structures of complexes 1 and 3 are confirmed by single crystal X-ray structure determination. Interaction of complexes 1–3 with DNA is explored by various spectroscopic techniques. The complexes 1–3 show solvent dependent photophysical properties. Complexes 2 and 3 show extensive “molecular light switch” effect for DNA. The complexes 1–3 are low toxic towards HeLa (human cervical cancer) and HL-60 (human promyelocytic leukemia) cell lines. Further, the cellular uptake of complexes 2 and 3 by cells shows that complexes mainly localised on the nucleus of the cells.

The tridentate phosphine ligand 1,3,5-tris[(E)-(4-phospholano-2,6-diethyl)styryl]benzene (1) reacts with [AuCl(tht)] (tht = tetrahydrothiophene) independent of the stoichiometry employed with selective formation of a two-dimensional coordination polymer (ratio 1 : 1) with the gold(I) cations in a trigonal-planar [3 + 1] coordination geometry. Each of the three coordinating phosphine units originates from another ligand, thus forming a polymeric structure.

The title pseudo-polymorph of 3-(triphenylphosphoranylidene)-2,5-dihydrofuran-2,5-dione crystallizes with a tetrahydrofuran solvent molecule, viz. C22H17O3P·C4H8O. The succinic anhydride ring is approximately planar (r.m.s. deviation = 0.032 Å). The tetrahydrofuran molecule is disordered over two orientations about a pseudo-twofold axis with refined occupancy ratio 0.718 (4):0.282 (4). In the crystal, C—H...O hydrogen bonds link molecules of the dihydrofuran-2,5-dione derivative into chains parallel to the b axis and arranged into layers stacked along [100] alternating with hydrogen-bonded tetrahydrofuran layers.

Carborane-substituted 1,2-diphosphetanes (Ia,b) react with elemental lithium in THF with cleavage of the P-P bond to give a deep red solution from which, in the case of Ia, red crystals of a lithiated intermediate, [{1-Li(THF)PtBu-6-PtBu-4,1,6-closo-Li(THF)C2 B10 H10 }{Li(THF)3 }]2 ⋅2 THF (2 a), are obtained. The compound is dimeric, C2 -symmetric and contains six lithium and four phosphorus atoms. Two lithium atoms cap the six-membered C2 B4 faces, resulting in two 13-vertex closo-clusters (according to Wade's rules) with docosahedral geometry. The addition of methyl iodide resulted in the formation of zwitterionic bis-phosphonium-nido-carborates 7,10-bis(tert-butyldimethylphosphonium)dodecahydro-7,10-dicarba-nido-dodecaborate(2-) (1 a) and 7,10-bis(N,N-diisopropylaminodimethylphosphonium)dodecahydro-7,10-dicarba-nido-dodecaborate(2-) (1 b) in moderate to good yields. Compounds 1 a and 1 b exhibit short Ccluster -P bonds and large Ccluster ⋅⋅⋅Ccluster distances in the solid state. Further insight into the ring opening and reduction potential of the alkyl halide was obtained from methylation reactions of different 1,2-bis-phosphinocarboranes. The reaction of rac-/meso-1,2-bis(tert-butylmethylphosphino)-1,2-dicarba-closo-dodecaborane(12) (3 a) with two equivalents of methyl iodide also resulted in the formation of 1 a (as shown by NMR spectroscopy), whereas the reaction of 1,2-bis(diphenylphosphino)-1,2-dicarba-closo-dodecaborane(12) with methyl triflate afforded the phosphonium salt 1-methyl-diphenylphosphonium-2-diphenylphosphino-1,2-dicarba-closo-dodecaborane(12) triflate (4) without reduction of the cluster.

The seven-membered cyclic bisphosphines 3–5 were synthesized by a Mannich-like condensation reaction of 1,2-bis(phenylphosphino)ethane, formaldehyde and primary amines (tert-butylamine, 1,1-(diphenyl)methylamine, (2R)-tetrahydro-2-furanylmethylamine) as a mixture of RPRP/SPSP (rac, 3a–5a) and RPSP (meso, 3b–5b) stereoisomers. The structures of the rac stereoisomers 3a–5a were investigated by X-ray crystal structure analyses. The RR/SS to RS isomerization of 3–5 and oxidation processes of 4 in solution were studied. Platinum(II) P,P-chelate complexes are formed exclusively from rac/meso mixtures of 3–5.

The oligophosphanylamine ligand 1,1,4,7,10,10-hexakis(diphenylphosphanyl)triethylenetetramine (1) was obtained from the reaction of triethylenetetramine with six equivalents of chlorodiphenylphosphine in good yield. Ligand 1 was treated with three equivalents of [Cr(CO)4(MeCN)2], [Mo(CO)4(nbd)] (nbd = norbornadiene), or [W(CO)4(MeCN)2] in toluene to give the trinuclear tetracarbonyl ­complexes [{M(CO)4}3{(PPh2)2N(CH2)2NPPh2(CH2)2NPPh2(CH2)2N(PPh2)2}-κ6P1,P2,P3,P4,P5,P6] [M = Cr (2), Mo (3), W (4)]. Compounds 1–4 were fully characterized by NMR (1H, 13C, 31P) and IR spectroscopy, elemental analysis and crystal structure determination (1–3). The molecular structures of 2 and 3 show the formation of tris-chelate complexes with two M–P–N–P four-membered rings and one M–P–N–CH2–CH2–N–P seven-membered ring.

3,4,5-Triphenyl-1-(+)-neomenthyl-1,2-diphosphole was obtained by alkylation of sodium 3,4,5-triphenyl-1,2-diphosphacyclopentadienide with (–)-menthyl tosylate. High delocalization within the planar heterocycle of the diphosphole is indicative of low aromaticity. Thus, the [4+2] cycloaddition reaction of this compound with maleic anhydride proceeded under mild conditions with high diastereoselectivity (up to 88 % de) and resulted in the corresponding enantiopure 1,7-diphosphanorbornadiene as an individual enantiomer. The observed high diastereoselectivity may be explained by thermodynamic control of the reaction.