Tetra-2,3-Pyrazinoporphyrazines with Externally Appended Pyridine Rings 22 Synthesis, Physicochemical and Photoactivity Studies on In(III) Mono- and Heteropentanuclear Complexes.

The basic macrocyclic octapyridinotetrapyrazinoporphyrazine In complex of formula [PyTPyzPzIn(OAc)]·8HO, prepared by reaction of the free ligand [PyTPyzPzH]·2HO with In(OAc), is a stable-to-air species of which the structure has been studied by its X-ray powder diffraction and mass spectra and characterization operated by IR and UV-visible spectral behavior. The complex has been further examined and proven to be of potential interest for its response as an anticancer agent in the field of photodynamic therapy (PDT), the value of Φ = 0.55 (in DMF) being in the range of 0.

Homo/Heteropentanuclear Porphyrazine Mg, Zn, and Pd Macrocycles with Externally Pending PdCl and Pd(CBT) Units: Synthesis, Physicochemical Characterization, and Photoactivity Studies.

Recent work has been developed on two new classes of neutral porphyrazine complexes of formulas [(PdCl)PyPzM]·HO (PyPz = octakis(2-pyridyl)porphyrazinato anion; M = Mg(HO), Zn, Pd) and [{Pd(CBT)}PyPzM]·HO (M = Mg(HO), Zn; CBT = -carborane-1-thiolate anion). Characterization of all the species has been conducted by IR and UV-visible spectral measurements in a systematic comparison with the corresponding already known mononuclear species [PyPzM] (M = Mg(HO), Zn) and the mono-Pd analogue isolated and presented here for the first time. Comparison includes also the two parent classes of pentanuclear tetrapyrazinoporphyrazines having the more extended π-electron delocalized macrocyclic core PyTPyzPz.

Bis(CBT)palladium(II) Derivatives (CBT = -carborane-1-thiolate): Synthesis, Molecular Structure, and Physicochemical Properties of -[(bipy)Pd(CBT)] and -[(py)Pd(CBT)].

The new synthesized Pd complex -[(bipy)Pd(CBT)] (bipy = 2,2'-bipyridyl; CBT = -carborane-1-thiolate anion), which is a potential BNCT (boron neutron capture therapy) agent and of structure elucidated by single-crystal X-ray work, has been studied by infrared (IR) and ultraviolet-visible light (UV-vis) spectra and its properties compared with those of the previously reported and also the structurally characterized analogue -[(py)Pd(CBT)]. This species, prepared via a direct method, was previously isolated from a pyridine solution, consequent to the occurring releasing of the external Pd(CBT) moieties of the porphyrazine macrocycle [{Pd(CBT)}LZn]·HO (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion), which is an active photosensitizer in photodynamic therapy (PDT) and a potential bimodal PDT/BNCT agent. The UV-vis spectral behavior of both and species in CHCl solution and in the gas phase has been examined in detail by density functional theory (DFT) and time-dependent density functional theory (TDDFT) studies devoted to explain their distinct behavior observed in the region of 400-500 nm, as determined by the presence in the structure of a vicinal arrangement of the two CBT groups, an ensemble of results closely similar to those observed for the macrocycles [{Pd(CBT)}LM]·HO (M = Mg(HO), Zn, Pd).

Palladium(II) and Platinum(II) Mononuclear Complexes and Tendency to Undergo Dehydrogenation of the Multiple N-Donor Ligand Di-(2-pyridyl)dihydropyrazine.

The already known di(2-pyridyl)dihydropyrazine (dhdpp) was prepared and isolated also in the form of a bis-hydrated species, i.e., dhdpp·2HO.

Characterization of tetrakis(thiadiazole)porphyrazine metal complexes by magnetic circular dichroism and magnetic circularly polarized luminescence.

The magnetic circular dichroism (MCD) spectra of metal complexes of tetrakis(thiadiazole)porphyrazines ([TTDPzM] with M = 2H , Zn , Mg (H O), and Cd ) have been recorded in dimethyl formamide solution. Together with the UV-Vis spectra, the MCD spectra provide useful information about the structure and electronic properties of the complexes. The experimental UV-Vis and MCD spectra compare pretty well with DFT calculations of two sorts, based either on the sum-over-states (SOS) approach or on the complex polarization propagator approach.

Tetra-2,3-pyrazinoporphyrazines with Peripherally Appended Pyridine Rings. 20. Mono- and Pentanuclear Al and Ga Complexes: Synthesis and Physicochemical and Photoactivity Studies.

The autocyclotetramerization of the precursor 2,3-dicyano-5,6-di(2'-pyridyl)pyrazine [(CN)PyPyz] in the presence of MCl compounds (M = Al, Ga) leads to the formation of the new mononuclear porphyrazine complexes [PyTPyzPzMCl]·HO (PyTPyzPz = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion). From these species, the hydroxide analogues [PyTPyzPzMOH]·HO were obtained by contact with hot water, and their corresponding pentanuclear species [(PdCl)PyTPyzPzMCl]·HO could be easily formed by the reaction with PdCl. Physicochemical characterization of the mono- and pentanuclear macrocycles was based on elemental analysis, and mass, powder X-ray, and IR spectra.

Tetrakis(1,2,5-thiadiazolo)porphyrazines. 9. Synthesis and spectral and theoretical studies of the lithium(i) complex and its unusual behaviour in aprotic solvents in the presence of acids.

The template cyclotetramerization of 1,2,5-thiadiazolo-3,4-dicarbonitrile in the presence of lithium n-butoxide in n-butanol leads to the Li(i) complex of tetrakis(1,2,5-thiadiazolo)porphyrazine. Various possible structures of dilithium and monolithium complexes have been considered by DFT/B3LYP molecular modelling using the cc-pvtz basis set, and their theoretical IR and UV-VIS spectra have been calculated. The experimental Li NMR, IR and UV-VIS spectra measurements show that the complex contains two inequivalent lithium atoms - one is coordinated to the macrocyclic dianion to form the anionic lithate complex [TTDPaLi], while the other forms the solvated countercation [Li(Solv)].

Tetra-2,3-pyrazinoporphyrazines with Peripherally Appended Pyridine Rings. 19. Pentanuclear Octa(2-pyridyl)tetrapyrazinoporphyrazines Carrying Externally Carboranthiolate Groups: Physicochemical Properties and Potentialities as Anticancer Drugs.

New pentanuclear porphyrazine complexes of formula [{Pd(CBT)}LM]· xHO (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion, CBT = m-carborane-1-thiolate, and M = Mg(HO), Zn, Pd) were prepared in good yield as dark green hydrated amorphous solids by reaction of the respective pentanuclear species [(PdCl)LM] with m-carboran-1-thiol in CHCN. Physicochemical characterization of the new species was carried out by elemental and thermogravimetric analysis along with IR and H/C NMR measurements. UV-vis spectral characterization performed in DMSO, DMF, and pyridine solution provided information about the stability of the new homo/heteropentanuclear species and their tendency to undergo detachment of the peripheral Pd(CBT) groups.

Photoactivity of New Octacationic Magnesium(II) and Zinc(II) Porphyrazines in a Water Solution and G-Quadruplex Binding Ability of Differently Sized Zinc(II) Porphyrazines.

The new octacations [(2-Mepy)PzM] [M = Mg(HO), Zn], isolated as iodide salts, were obtained from the corresponding neutral complexes [PyPzM] (Py = 2-pyridyl; Pz = porphyrazinato dianion) upon quaternization with CHI of the N atoms of the 2-pyridyl rings under mild experimental conditions. The absorption spectra registered in organic solvents as well as in water (HO) confirm the presence of the complexes in their monomeric form in all cases. The two octacations behave as photosensitizers in a HO/sodium dodecyl sulfate solution for the production of singlet oxygen, O, and exhibit quantum yield values (Φ) 2.

Octakis(2-pyridyl)porphyrazine and Its Neutral Metal Derivatives: UV-Visible Spectral, Electrochemical, and Photoactivity Studies.

Tetrapyrrolic porphyrazine macrocycles with externally appended 2-pyridyl rings were synthesized and characterized as to their spectroscopic, electrochemical, and photophysical properties. The investigated compounds are represented as [PyPzH], the unmetalated octakis(2-pyridyl)porphyrazine, and the metal complexes [PyPzM], where M is Mg(HO), Cu, Zn, or Co. The spectroscopic properties and the electrochemical behavior of these compounds were examined in solution of polar (pyridine, dimethyl sulfoxide, and dimethylformamide) and nondonor solvents (CHCl, CHCl), and the data were compared with those obtained from earlier studies on the related tetrapyrazinoporphyrazines, [PyTPyzPzM], and the tetraquinoxalinoporphyrazines, [PyQxPzM], also bearing externally 2-pyridyl rings, and characterized by a more extended central π-conjugated macrocyclic framework.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 17. Photosensitizing properties and cellular effects of Zn octacationic and Zn/Pt hexacationic macrocycles in aqueous media: Perspectives of multimodal anticancer potentialities.

The photosensitizing activity of two multiply charged porphyrazine derivatives, i.e. the Zn species [(CH)LZn] and the Zn/Pt heterobimetallic complex [(PtCl)(CH)LZn] (neutralized byI ions; L=tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato dianion) has been examined in the water medium in the presence of SDS under experimental conditions in which the two species are present exclusively in their monomeric form.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 15. Effects of the pyridyl substituents and fused exocyclic rings on the UV-visible spectroscopic properties of Mg(II)-porphyrazines: a combined experimental and DFT/TDDFT study.

Two new Mg(II) porphyrazine macrocycles, the octakis(2-pyridyl)porphyrazinato-magnesium(II), [Py8PzMg(H2O)], and the tetrakis-[6,7-di(2-pyridyl)quinoxalino]porphyrazinato-magnesium(II), [Py8QxPzMg(H2O)], were prepared by Mg-template macrocyclization processes, and their general physicochemical properties were examined. The previously reported porphyrazine analog, the tetrakis-2,3-[5,6-di(2-pyridyl)-pyrazino]porphyrazinato-magnesium(II), [Py8PyzPzMg(H2O)], has been also considered in the present work. The UV-visible solution spectra in nonaqueous solvents of this triad of externally octapyridinated Mg(II) complexes exhibit the usual profile observed for phthalocyanine and porphyrazine macrocycles, with intense absorptions in the Soret (300-450 nm) and Q band (600-800 nm) regions.

Pyrazinoporphyrazines with externally appended pyridine rings. 13. Structure, UV-visible spectral features, and noncovalent interaction with DNA of a positively charged binuclear (Zn(II)/Pt(II)) macrocycle with multimodal anticancer potentialities.

We investigated with spectroscopic techniques the noncovalent interaction of a bimetallic water-soluble (Zn(II)/Pt(II)) porphyrazine hexacation, [(PtCl(2))(CH(3))(6)LZn](6+), and its octacationic analogue [(CH(3))(8)LZn](8+), lacking the cis-platin-like functionality, with a 21-mer double strand (ds) 5'-d[GGG(TTAGGG)(3)]-3'/3'-d[CCC(AATCCC)(3)]-5', as model for B-DNA. Both hexacation and octacation tend to aggregate in water. The structure as well as the ground and excited-state electronic properties of the Zn(II)/Pt(II) hexacation [(PtCl(2))(CH(3))(6)LZn](6+) in water solution were investigated using density functional theory (DFT) and time-dependent DFT (TDDFT) methods.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 12. New heteropentanuclear complexes carrying four exocyclic cis-platin-like functionalities as potential bimodal (PDT/cis-platin) anticancer agents.

Heteropentanuclear porphyrazines having the formula [(PtCl2)4LM] where L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato dianion and M = Zn(II), Mg(II)(H2O), Pd(II), Cu(II) or Co(II) were characterized by elemental analyses, IR-UV-visible spectroscopy and electrochemistry and the data compared to new and previously published results for the corresponding homopentanuclear compound [(PtCl2)4LPt]. This latter species has four external N2(py)PtCl2 coordination sites which closely resemble cis-platin, (NH3)2PtCl2, the potent chemotherapeutic anticancer drug, and is able to act as a photosensitizer for the generation of (1)O2, the cytotoxic agent in photodynamic therapy (PDT). UV-visible spectra and half wave potentials for reduction of [(PtCl2)4LM], [(PtCl2)4LPt], the parallel series of mononuclear [LM] compounds and the pentanuclear [(PdCl2)4LM] compounds were examined in the nonaqueous solvents dimethyl sulfoxide, pyridine, and dimethylformamide.

Tetrakis(thiadiazole)porphyrazines. 8. Singlet oxygen production, fluorescence response and liposomal incorporation of tetrakis(thiadiazole)porphyrazine macrocycles [TTDPzM] (M = Mg(II)(H2O), Zn(II), Al(III)Cl, Ga(III)Cl, Cd(II), Cu(II), 2H(I)).

The photoactivity for the generation of singlet oxygen, (1)O(2), the key cytotoxic agent in the anticancer treatment known as photodynamic therapy (PDT), and the fluorescence response of the highly electron-deficient tetrakis(thiadiazole)porphyrazines of formula [TTDPzM] (M = Mg(II)(H(2)O), Zn(II), Al(III)Cl, Ga(III)Cl, Cd(II), Cu(II), 2H(I)) were examined (c ≅ 10(-5) M) in dimethylformamide (DMF) and/or in DMF preacidified with HCl (DMF/HCl; [HCl] = 1-4 × 10(-4) M). The singlet oxygen quantum yield (Φ(Δ)) of all the compounds was determined by using a widely employed procedure based on the selective oxidation of the 1,3-diphenylisobenzofuran (DPBF), modified in part as reported. The list of the Φ(Δ) values indicates excellent photosensitizing properties for the series of compounds carrying "closed shell" metal ions, with values measured in DMF/HCl respectful of the "heavy atom effect" for the first four lighter centers, increasing in the order Mg(II) < Al(III) < Zn(II) < Ga(III).

Crystal structure, spin polarization, solid-state electrochemistry, and high n-type carrier mobility of a paramagnetic semiconductor: vanadyl tetrakis(thiadiazole)porphyrazine.

We report the synthesis, crystal structure, and magnetic, electrochemical, and carrier-transport properties of vanadyl tetrakis(thiadiazole)porphyrazine (abbreviated as VOTTDPz) with S = ½. X-ray crystal analysis reveals two polymorphs, the α and β forms; the former consists of a 1D regular π stacking, while the latter forms a 2D π network. Molecular orbital calculations suggest a V(4+)(d(1)) ground state and a characteristic spin polarization on the whole molecular skeleton.

Structural flexibility and role of vicinal 2-thienyl rings in 2,3-dicyano-5,6-di(2-thienyl)-1,4-pyrazine, [(CN)2Th2Pyz], its palladium(II) complex [(CN)2Th2Pyz(PdCl2)2], and the related pentametallic pyrazinoporphyrazines [(PdCl2)4Th8TPyzPzM] (M = Mg(II)(H2O), Zn(II)).

The solid state and solution structure of 2,3-dicyano-5,6-di(2-thienyl)-1,4-pyrazine, [(CN)(2)Th(2)Pyz], and its Pd(II) derivative, [(CN)(2)Th(2)Pyz(PdCl(2))(2)]·H(2)O, formed by reaction of [(CN)(2)Th(2)Pyz] with [(C(6)H(5)CN)(2)PdCl(2)] were characterized by X-ray, UV-visible, (1)H and (13)C NMR, and extended X-ray absorption fine structure (EXAFS) spectral measurements. The X-ray crystal structure of [(CN)(2)Th(2)Pyz] shows the presence of one thienyl ring positioned orthogonal to the rest of the molecule, with the two vicinal thienyl rings lying orthogonal to each other in a rare arrangement. NMR studies of [(CN)(2)Th(2)Pyz] in the solid state and in solutions of dimethylformamide or dimethyl sulfoxide confirm a nonequivalence of the thienyl rings in the solid state and also in solution.

Tetra-2,3-pyrazinoporphyrazines with externally appended thienyl rings: synthesis, UV-visible spectra, electrochemical behavior, and photoactivity for the generation of singlet oxygen.

A series of pyrazinoporphyrazine macrocycles carrying externally appended 2-thienyl rings, represented as [Th(8)TPyzPzM], where Th(8)TPyzPz = tetrakis-2,3-[5,6-di(2-thienyl)pyrazino]porphyrazinato anion and M = Mg(II)(H(2)O), Zn(II), Co(II), Cu(II), or 2H(1), were prepared and isolated as solid air-stable hydrated species. All of the compounds, completely insoluble in water, were characterized by their UV-visible spectra and electrochemical behavior in solutions of dimethylformamide (DMF), dimethyl sulfoxide, and pyridine. Molecular aggregation occurs at concentrations of ca.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 9. Novel heterobimetallic macrocycles and related hydrosoluble hexacations as potentially active photo/chemotherapeutic anticancer agents.

New homo- and heterobimetallic porphyrazine complexes of general formula [(M'Cl(2))LM] (L = tetrakis-2,3-[5,6-di-(2-pyridyl)pyrazino]porphyrazinato dianion), with M = Zn(II), Mg(II)(H(2)O), or Pd(II) in the central cavity and one M'Cl(2) unit (M' = Pd(II), Pt(II)) peripherally coordinated at the pyridine N atoms of one of the dipyridinopyrazine fragments, were prepared and characterized by elemental analyses and IR/UV-visible spectroscopy. Related water-soluble salt-like species, carrying the hexacations [(PtCl(2))(CH(3))(6)LM](6+) (neutralized by I(-) ions), were also prepared and similarly characterized. Retention of clathrated water molecules is a common feature of all the compounds.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 10. A water-soluble bimetallic (Zn(II)/Pt(II)) porphyrazine hexacation as potential plurimodal agent for cancer therapy: exploring the behavior as ligand of telomeric DNA G-quadruplex structures.

The behavior of a bimetallic water-soluble (Zn(II)/Pt(II)) porphyrazine hexacation as ligand of G-quadruplex (G4) structures adopted by a human telomeric DNA sequence has been examined with different spectroscopic techniques. In K(+) rich solution the hexacationic Zn(II) porphyrazine ligand bearing a peripheral cis-platin-like functionality changes the G-quadruplex conformational equilibrium of the human telomeric sequence 5'-d[AGGG(TTAGGG)(3)]-3' and drives it exclusively toward a very stable parallel G4 form in the complex with 2:1 stoichiometry. An increase of the melting temperature of more than 20 °C is observed in this complex compared to the G4 alone.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 8. Central (Zn(II), Cu(II), Mg(II)(H2O), Cd(II)) and exocyclic (Pd(II)) metal ion binding in heteropentametallic complexes from tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazine.

A series of heteropentametallic porphyrazine macrocycles, represented as [(PdCl(2))(4)LM], where L = dianion of tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazine and M = Zn(II), Cu(II) Mg(II)(H(2)O) or Cd(II), were prepared by reaction of the corresponding mononuclear [LM] species, and their behavior was examined by UV-visible and NMR spectroscopy, electrochemistry, and thin layer spectroelectrochemistry in nonaqueous media. The PdCl(2) units in [(PdCl(2))(4)LM] are coordinated at the pyridine N atoms of the external dipyridinopyrazine fragments ("py-py" coordination) and are displaced out of the plane of the central pyrazinoporphyrazine macrocycle as verified by (1)H and (13)C NMR data on [(PdCl(2))(4)LZn]. The same arrangement is also strongly suggested by similar NMR data on the Mg(II) and Cd(II) analogues.

Tetrakis(thiadiazole)porphyrazines. 6. Spectroelectrochemical and density functional theory studies of the anions [TTDPzM](n-) (n = 1-4; M = Zn(II), Mg(II)(H(2)O), Cu(II), 2H(I)).

Following previous cyclic voltammetric studies of tetrakis(thiadiazole)porphyrazines [TTDPzM] where M = Zn(II), Mg(II)(H(2)O), Cu(II), or 2H(I) in nonaqueous media, a thin-layer spectroelectrochemical investigation was carried out in pyridine to characterize each stepwise one-electron reduction of the electrogenerated [TTDPzM](n-) complexes where n = 1-4. A similar UV-visible spectrum was observed for each form of the anion, independent of the central metal ion and detailed theoretical calculations by density functional theory (DFT) and time-dependent DFT (TDDFT) methods were applied to interpret the spectral features of [TTDPzZn](n-) (n = 1-4) which was selected as representative for describing the ground and excited-state electronic structures of the entire [TTDPzM](n-) series. The use of two exchange-correlation functionals, the pure, asymptotically correct statistical average of orbital potentials (SAOP) and the hybrid B3LYP functionals, proved to be essential for attaining a correct assignment of the key spectral features.

Structural, UV-visible, and electrochemical studies on 2,3-dicyano-5,6-di-2-pyridylpyrazine, [(CN)2Py2Pyz], related species and its complexes [(CN)2Py2PyzMCl2] (M = Pt(II), Pd(II)).

2,3-Dicyano-5,6-di-2-pyridylpyrazine, [(CN)(2)Py(2)Pyz], which autocyclotetramerizes to give the macrocycle tetrakis[5,6-di(2-pyridyl)-2,3-pyrazino]porphyrazine, [Py(8)TPyzPzH(2)], bearing externally four dipyridinopyrazine fragments, reacts with bis(benzonitrile)dichloroplatinum(II), [(C(6)H(5)CN)(2)PtCl(2)], in CH(3)CN, affording the monometalated species [(CN)(2)Py(2)PyzPtCl(2)]. Single-crystal X-ray work on this compound shows that Pt(II) is bound to [(CN)(2)Py(2)Pyz] through the two pyridine N atoms ("py-py" coordination) in a way similar to that found for its monopalladium analogue, [(CN)(2)Py(2)PyzPdCl(2)]. Cyclic voltammetry of [(CN)(2)Py(2)PyzPtCl(2)] and [(CN)(2)Py(2)PyzPdCl(2)] in nonaqueous media (pyridine, DMSO, and DMF) indicates that the electron-withdrawing effect of the coordinated PtCl(2) and PdCl(2) units results in an initial one-electron reduction (E(1/2) = -0.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 6. Chemical and redox properties and highly effective photosensitizing activity for singlet oxygen production of penta- and monopalladated complexes in dimethylformamide solution.

Tetrakis-2,3-[5,6-di-(2-pyridyl)pyrazino]porphyrazinatopalladium(II) [Py 8TPyzPzPd] ( 1) and the corresponding pentapalladated species [(PdCl 2) 4Py 8TPyzPzPd] ( 2), dissolved (c approximately 10 (-5)-10 (-6) M) in preacidified dimethylformamide ([HCl] approximately 10 (-4) M), behave as potent photosensitizing agents for the production of singlet oxygen, (1)O 2, with Phi Delta values of 0.89 +/- 0.04 and 0.

Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 5. Synthesis, physicochemical and theoretical studies of a novel pentanuclear palladium(II) complex and related mononuclear species.

New palladium(II) complexes of the free-base tetrakis[2,3-(5,6-di-2-pyridylpyrazino)porphyrazine], [Py 8TPyzPzH 2], have been prepared and their physicochemical properties examined. The investigated compounds are the pentanuclear species [(PdCl 2) 4Py 8TPyzPzPd], the monopalladated complex [Py 8TPyzPzPd], and its corresponding octaiodide salt [(2-Mepy) 8TPyzPzPd](I) 8. All three Pd (II) complexes have a common central pyrazinoporphyrazine core and differ only at the periphery of the macrocycle, where the simple dipyridinopyrazine fragments present in [Py 8TPyzPzPd] bear four PdCl 2 units coordinated at the pyridine N atoms in the pentanuclear complex, [(PdCl 2) 4Py 8TPyzPzPd], or carry pyridine-N(CH 3) (+) moieties in the iodide of the octacation [(2-Mepy) 8TPyzPzPd] (8+).