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IntroductionSmoke-free legislation has been instrumental in reducing secondhand smoke (SHS) exposure in public places. However, the evidence of the impact of institutional smoke-free policies in settings such as healthcare and defence is weaker. Specifically, the literature on the effect of smoke-free policies in military settings has not yet been synthesised.MethodsThis review aimed to identify, critically appraise and synthesise the available evidence to evaluate the effect of defence smoke-free policies on SHS exposure. Eight electronic databases (eg, EMBASE, MEDLINE) were searched from inception to June 2020. We included English-language studies on smoke-free policies introduced in a defence setting, assessing their impact on SHS exposure (primary outcome) and healthcare utilisation, smoking behaviours and defence efficiency (secondary outcomes). Risk of bias was assessed using ROBINS-I. Synthesis without meta-analysis was conducted using vote counting of direction of effect.ResultsThe search retrieved 4503 citations of which eight met inclusion criteria; two controlled and six uncontrolled before-and-after studies. The evidence, although low-quality, from one study indicated reduced SHS exposure following the introduction of a defence smoke-free policy. For secondary outcomes the review found mixed results, with the quit rate being the one outcome favouring smoke-free policies. The cumulative confidence of evidence is uncertain and therefore reliable conclusions cannot be drawn from these studies.ConclusionsA research gap exists for high-quality studies on the impact of defence smoke-free policies which should use comparators and, if possible, randomisation. Policy-makers should introduce institutional smoke-free policies in defence settings within an evaluative framework to generate such evidence.

Sodium deoxycholate (a biosurfactant) in planar chromatography has been used to investigate the separation and migration behavior of transition metal ions. The chromatographic system comprised of soil-cellulose (3:7, w/w) as stationary phase and mixed micellar solution (sodium deoxycholate-sodium dodecyl sulfate, 1.0% each in 1:1 ratio) containing M5-acetonitrile in 3:2 ratio (v/v) was identified as the best mobile phase for separation and migration of transition metal ions. The Rfvalue for the metals follows the order, Cu(II) (0.15) < Ag(I) (0.57) < Au(III) (0.91) which also happens to be the order of increasing atomic weight of the metal ions in the periodic group. The detection limit of Cu(II), Ag(I), and Au(III) was found to be 0.22, 1.48, and 7.76 µg zone-1respectively. The proposed method is robust, sensitive, easy, and reproducible. It has been used for successful identification and separation of above mentioned cations in sample matrices.

Four novel N4-type macrocyclic chelating agents L1, L2, L3, L4 with pendant groups and their metal chelates with some transition metal ions have been synthesized. Electrical conductance of the Cr(III) and Fe(III) chelates indicated them to be 1:1 electrolytes whilst those of divalent metal ions are non-electrolytes in DMSO. Spectroscopic evidence suggests that all of the complexes are six-coordinate and the pendant groups are not involved in coordination.

[Bis(propanediamine)Cu]Cl2, (1) was allowed to react with SiCl4 to yield a bimetallic complex (2). Compound (2) was then treated with pyridine to attain the maximum coordination number of silicon (3). The reaction was also followed conductometrically. Complex (3) was reacted with sodium diethyl dithiocarbamate (dtc) to yield (4). The dtc in (4) acts as a bidentate chelating agent as its IR spectrum showed the CS2 stretching frequency at 1020 cm-1 which is characteristic of a symmetrically bonded dithiocarbamate group. There is a common peak in the range 246 to 260 nm in the UV-Vis. spectra of (1), (2) and (3) due to L→M charge transfer. The EPR spectra of all species showed different environments for the Cu(II) ion in the various compounds indicating stereochemical changes.

The sodium salts of pyrimidinetrione dithiocarbamate (NaL1) and pyrimidinetrione dithiocarbamate (Na2L2) and their first row-transition metal complexes of the type [M(L1)2], [M'(L1)3] and [M2(L2)2], where M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and M'=Cr(III), Fe(III) have been synthesized and characterized. Spectroscopic studies suggest that the interaction of L2 with a divalent metal ion forms binuclear dithiocarbamate macrocyclic complexes. Conductivity measurements reveal that all of the complexes are non-electrolytes. The magnetic moment values and electronic spectra suggest that the Mn(II) and Co(II) complexes are tetrahedral, the Ni(II) and Cu(II) complexes are square-planar while the Fe(III) and Cr(III) complexes are proposed to have an octahedral structure.

Trinuclear macrocyclic metal complexes having oxamide bridges have been synthesized by the interaction of the macrocycle 1,4,7,10-tetraazacyclotetradecane-2,3-dione with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) chlorides and were characterized.by elemental analyses, EPR, electronic, IR, 1H NMR spectra, conductivity and magnetic susceptibility measurements. The conductivity measurements suggest that the complexes of the divalent metal ions are nonionic while those of the trivalent metal ions appear to be 1:3 electrolytes. On the basis of electronic spectra and magnetic moment values an octahedral geometry is proposed for all of the prepeared complexes.

The direct reaction of triethylenetetramine and diethyl oxalate in DMF in a 1:1 ratio results in the formation of the 12-membered tetraazamacrocycle triethylenetetramine oxamide (L). A condensation reaction of triethylenetetramine and diethyl oxalate in the presence of divalent hydrated transition metal chlorides (Mn2+, Co2+, Ni2+, and Cu2+) and ZnCl2 in absolute methanol in a similar ratio (1:1:1) yields ionic 12-membered macrocyclic complexes. The results show that two water molecules are bound to the central metal ion (Mn2+, Co2+, Ni2+ and Cu2+) resulting in an octahedral environment while zinc maintains a tetrahedral geometry for being free from water. The i.r. spectral bands show that the two C=O groups of the oxalato species do not participate in coordination. The slight decrease in (C=O) suggests bonding of the nitrogen of the amide group to the metal ion. The complexes decompose on dissolution in DMSO.

The new macrocyclic ligand 1,4,8,11-tetraazacyclotetradeca-2,3,9,10-tetrathio-5,7,12,14-tetramethyl-4,6,11,13-tetraene has been prepared by the condensation of dithiooxamide with acetylacetone. New transition metal complexes of the type [M(L)Cl2] (M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) and [M(L)Cl2]Cl [M = Cr(III), Fe(III)] have been synthesized and characterized. Molar conductance values revealed that the complexes of bivalent metal ions are non-ionic while those of trivalent metal ions are 1:1 electrolytes in DMSO. Their electronic spectra and magnetic moments are suggestive of an octahedral geometry.

Pyrrolidine-N-carbodithioate and its complexes of the type M(S2CNC4H8)4, MCl2(S2CNC4H8)2 and Sn(S2CNC4H8)2Bu2 (where M = Si, Ge, Sn, Ti or Zr and Bu = butyl) have been synthesized and characterized. The results indicate that M(S2CNC4H8)4 complexes have octahedral geometry with two symmetrically and two unsymmetrically bound dithiocarbamate moieties while M(S2CNC4H8)2Cl2 and Sn(S2CNC4H8)2Bu2 have octahedral geometry with two bidentate dithiocarbamates.

A new macrocyclic Schiff base 1, 2, 4, 8, 10, ll-hexaza-3, 9-bis-4-pyrido-tetradeca-3, 9, 12, 14-tetraene (HPT) on reaction with lanthanide chlorides yields complexes of general formula [MCl3(C20H24N8)][M = Ce(III), Pr(III), Dy(III), Sm(III), Gd(III) and Nd(III)]. These complexes were characterized by elemental analysis, i. r., UV-visible spectral studies, conductance and magnetic moment measurements. The magnetic moments and electronic spectra suggest that the lanthanide ions are 7-co -ordinate.

Fropanediamine dithiocarbamate and its metal complexes with MCl4. (Si = M Ge, Sn, Ti, and Zr) and Ph2-SnCl2 have been synthesized and characterized. The results indicate that MCI4. reacts in a 1, 4 (metal : dithiocarbamate) ratio yielding an octahedral compound with two symmetrically and two unsym-metrically bound dithiocarbamato groups while Ph2SnCl2 reacts in a 1: 1 ratio leading to the formation of a stable five-coordinate complex with the phenyl groups occupying the equatorial positions.

New heterobimetallic chelates [CuLMCl4] [M = Si, Ge, Sn, Ti and Zr; L = NN'-ethylenebis(salicylideneiminate)] prepared by treating CuL with Group IV metal tetrachlorides in a 1:1 ratio were characterized by e. s. r., electronic and i. r. spectroscopy, elemental analysis and conductivity measurements. The e. s. r. spectral g-values indicate square planar environments for copper(II) in both CuL and [CuLMCl4]. Conductivity measurements show that the heterobimetallic chelates are non-electrolytes. The phenolic C-O stretching frequency shifts to higher frequencies in the i. r. spectra of auducts suggesting that a coordinate bond is formed between oxygen of CuL and the Group IV metal.

Chelates of La(III), Ce(III), Pr(III), Nd(III), Gd(III), Dy(III) and Er(III) with 2,2'-bis-(1H,3H,5H)-pyrimidine-4,6-dione-[l,3] diiminopropane and 2,2'-bis-5,5-diethyl-(1H, 3H)-pyrimidine-4,6-dione-[1,3]-diiminopropane have been synthesised and characterised on the basis of IR, UV-Vis spectroscopy (reflectance), elemental analysis and magnetic moment measurements. The ligands act as tetradentate chelating agents coordinating through two C=N and two NH nitrogens. The LD50 towards cockroaches of both the ligands and complexes indicate that the complexes are more toxic than the ligands.

Complexes of Cu(II) and Ni(II) with the Schiff base (SB-H2) derived from the condensation of 2-amino-3-formylchromone and 1, 3-diaminopropane have been synthesised. Treatment of these complexes with Group IV metal tetrachlorides gave heterobimetallic chelates of the type [M(SB)M'Cl2]Cl2-which have been characterized by elemental analyses, IR, UV/vis, EPR spectroscopy and molar conductance measurements. The complexes are ionic in nature and the g values of the EPR spectrum of the copper(II) complex indicate that it has a distorted octahedral geometry.

The synthesis of new compounds of the type MCI4 L, R2SnCl2L, R3SnClL and R4SnL (M = sl, Ge, Sn, Tl and zr; L = methylenebis (piperidinedithiocarbamate) and R = phenyl) are reported. The results indicate the coordination of the two terminal sulphur atoms (C=S) to the metal results in the formation of eight-membered ring complexes. An octahedral geometry has been proposed for the Group IV metal in which the chlorines are adopting cis-configuration.

A systematic study of the chelating nature of Schiff bases (SB) derived from sulphamerazine and aldehydes has been made. These bases containing O-N and N-N donor sites act as monobasic bidentate chelating agents. An attempt has been made to elucidate the structure of lanthanide chelates with these Schiff bases on the basis of conductance, magnetic moments and spectral data.The stability constants of the metal chelates evaluated potentiometrically follow the order La < Ce < Pr < Nd < Dy < Er.

Schiff bases from S-benzoyl dithiocarbamate and thiophene 2-aldehyde (A) and 4-N-N-dimethyl aminobenzaldehyde (B) have been synthesized. Their complexes of the type (Ml2Cl)2.4H20 with lanthanides have been characterized on the basis of IR, NMR and UV-visible spectroscopy, elemental analysis and magnetic moment measurements. The nephelauxetic effect (1-β), bonding parameter β b1/2, Sinha covalency parameter δ and the molar conductance measurement in nitrobenzene reflect covalent nature for the complexes. The stability constants and other thermodynamic data have been determined in aqueous solutions at 25, 30 and 35°C. The toxicity of the Schiff bases and their complexes were evaluated against insects and fungi. The LD50 for cockroaches and percent growth inhibition of fungi show greater efficacy for the complexes than for the Schiff bases.

The potassium salts of the three new potential chelating ligands dihydrobis-, hydrotris- and tetrakis(6-nitro-indazoly1)borate anions have been synthesized by refluxing potassium borohydride and 6-nitroindazole in DMF in the appropriate molar ratio. These salts have been used to form complexes with the 3d transition metal ions vanadium through copper. The complexes of dihydrobis(6-nitroindazoly1)borate anion with V(III) and Fe(III) are octahedral, whereas Mn(II), Co(II), Ni(II) and Cu(II) complexes have tetrahedral geometry. The Cr(II) complex has been observed to be tetragonally distorted. The hydrotris(6-nitroindazoly1)borate anion gave rise to only octahedral complexes of the above metal ions except for Cr(II) and Cu(II) which gave rise to complexes with tetragonally distorted octahedral geometry. The tetrakis(6-nitroindazoly1)-borate anion is found to be a substituted variant of the hydrotris ligend.

Three new ligands, potassium dihydrobis-, potassium hydrotris- and potassium tetrakis(indolyl)borates and their complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized. The divalent and trivalent metal ions form complexes in 1:1 and 1:2 (metal:ligand) ratios, respectively. They were characterized by elemental analysis, magnetic susceptibility measurements, electronic and infrared spectra. On the basis of these studies Cr(III) and Fe(III) complexes with dihydrobis- and hydrotris(indolyl)borates appear to be octahedral. The divalent metal ions are supposed to have tetrahedral geometry excepting the Cu(II) for which a square planar structure is proposed. The tetrakis(indolyl)borate yielded octahedral complexes with all the above metal ions. The ligand field parameters 10Dq, B and β have also been evaluated in some cases.

A new tetradentate ligand 1,3-pyrimidinyl(2,4,6-pyrimidine trione) and its chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) complexes have been prepared and characterized by elemental analysis, magnetic susceptibility measurements, and electronic and i.r. spectra. Conductivity measurements show the complexes to be non-electrolytes. An octahedral geometry for trivalent ions [iron(III) and chromium(III)] has been proposed, whereas all divalent metal ions, except for copper(II), appear to be tetrahedral. The 10 Dq values suggest that the ligand is as strong as ethylenediamine. The ß values indicate a considerable orbital overlap in the metal-ligand bond.

A series of lanthanide complexes of the type, ML3.2H2O with a Schiff base derived from sulphafurazole and salicylal-dehyde has been characterized by elemental analysis, infrared spectroscopy and molar conductance measurements. The Schiff base acts as a monobasic bidentate ligand bonding to the metal via a nitrogen and a phenolic oxygen atom and the complexes appear to be eight coordinated.

Heterobimetallic complexes of the type [Cu(TETA) C12MCl2] where M = Si, Ge, Sn, Ti or Zr, TETA-H2 = (triethylene tetramine) have been synthesized and characterized by elemental analysis, EPR spectra, electronic spectra, IR spectra, far-IR spectra and conductivity measurements. The complex [Cu(TETA)Cl2 SnPh2] has also been prepared. The results indicate that the compound [Cu(TETA-H2)]Cl2 is square planar and ionic in nature, while its bimetallic complexes, [Cu(TETA)Cl MCl2] and [Cu(TETA)Cl2SnPh2], have an octahedral environment around the Cu(II) ion. Another series of compounds of the type [Cu(TETA)C12M(TMDTC)2] has been prepared by the direct interaction of [Cu(TETA)Cl MCl2] with tetramethylenedithiocarbamate (TMDTC) in a 1:2 ratio in methanol. In these complexes, an octahedral stereochemistry around the Group IV metal has been observed in which the TMDTC acts as a bidentate ligand.

ML2Cl.2H2O type complexes of lanthanide(III) ions with a Schiff base derived from salicylaldehyde and S-benzoyl p-amino benzene sulphonamide dithiocarbamate were synthesized and characterized by elemental analysis, IR, NMR, and UV-Visible spectroscopy, molar conductance and magnetic moment measurements. Stability constants of the complexes in solution were determined potentiometrically.

2-(N-succinimidyl) pyrimidine complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Hg(II), Ru(III) and Pd(II) have been prepared and characterized by elemental analyses, IR, UV-Vis spectra and magnetic moment measurements. High melting points and non-solubility in common organic solvents indicate their polymeric nature. The Ru(III), Pd(II) and Cu(II) complexes are soluble in DMSO. The low molar conductance of these complexes indicates their non-electrolytic nature. The observed magnetic moment values of the complexes are very close to those calculated for the metal in an octahedral environment of ligands. The values of 10Dq, B and have also been determined in cases where possible.

Stable transition metal [Co(II), Ni(II), Cu(II), Mn(II) and Zn(II)] chelates with the title compound have been prepared. Their structures have been assigned on the basis of analytical, spectral (IR and visible), conductance and magnetic data.

Lanthanide(III) ion chelates with a Schiff base derived from sulphapyridine and salicylaldehyde have been characterised by molar conductance, magnetic moment and spectral data. Coordination of the lanthanide ions occurs through both the phenolic oxygen and the azomethine nitrogen of the Schiff base and two water molecules.The stability constants of the metal chelates were determined potentiometrically and followed the order La < Ce < Pr = Nd < Dy < Er. A plot of log K versus e 2/r shows an approximately linear relationship.

A few transition metal complexes of 2-thiobarbituric acid (TBA) have been synthesized and characterized by chemical analyses, i.r.- and reflectance spectroscopic studies and magnetic susceptibility measurements. On the basis of these studies Cu(II), Cd(II) and Pd(II) complexes have been proposed to have square-planar geometry While those of Mn(II), Fe(III), Co(II), Ru(III), Rh(III), Ir(III) and Pt(IV) were found to be octahedral. Mn(II), Cu(II), Co(II) and Fe(III) complexes are magnetically subnormal. TBA has been found to act as a bidentate or quadridentate ligand. The sulphur atom in no case has been claimed as a coordination site. Metal ligand stretching frequencies occur in the range 175-270 cm-1 for first row transition metals and Cd(II), which follow the Irwing-Williams sequence of metal ions:

Complexes of homocystine, [-SCH2CH2CH(NH2)COOH]2, have been prepared with Cr(II), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) chlorides. They have been characterized by elemental analyses, diffuse reflectance spectra and magnetic susceptibility measurements. The elemental analyses indicates a 1:1 metal: ligand ratio. The divalent metal ions are coordinated through all the donor sites of the amino acid while trivalent iron seems to be coordinated only through nitrogen and oxygen with bridging chlorine atoms. The spectral and magnetic data suggest an octahedral metal environment in all these complexes except for Zn(II) and Cd(II).

Trimethyltin(IV) chloride, triphenyltin(IV) chloride and tributyltin (IV) chloride adducts of piperazine (Pz), acridine (Acr), pyrrolidine (Pyrr), phenenthroline (phen) and 2,2'-bipyridyl (Bipy) have been synthesized and characterized on the basis of elemental analysis, I. R. spectroscopy and conductivity measurements. The adducts have been found to have a 1:1 metal to ligand ratio and exhibit nonionic character in nitrobenzene or methanol. A trigonal bipyramidal geometry has been proposed for acridine, piperazine and pyrrolidine complexes while phenanthro-line and 2,2'-bipyridyl adducts seemed to have an octahedral geometry.

A novel ligand, potassium tetrakis(1-indazolyl)borate has been synthesized from potassium borohydride and indazole at 215°C in a closed assembly. Complexes of this newly synthesized chelate have been prepared with Cu(II), Ni(II), Co(II), Mn(II) and Fe(III) halides. These have been characterized by elemental analysis, IR, reflectance spectra, room temperature magnetic susceptibility- and conductance measurements. Except for the Cu(II) complex, these complexes appear to have an octahedral structure. The molar conductance value of 10-3M solutions of all complexes, except the Ni(II) complex, support nonionic species. B and 10 Dq values have been calculated where appropriate.

Piperazine bis(dithiocarbamate) (pzbisdtc) and diethyl dithiocarbamate (ET2dtc) complexes of R3SnX (where R = phenyl, methyl, butyl; X = acetate, chloride) have been synthesized and characterized by elemental analysis and I.R. spectral studies. The complexes formed have a 1:1 (M:L) ratio except (Ph3Sn)2Pz bisdtc. The compounds are thermally stable and insensitive to moisture. In all the cases the dithiocarbamato moiety has been found to be symmetrically coordinated to the tin atom.

The complexes of 2,5-dimercapto-1, 5-dimercapto-1, 3, 4-thiadiazole (bismuthiol I, BT), 2-aminothiazole (AT) and 2-amino-6-ethoxybenzothiazole (AEB) with SnCl4, SnBr4 and GeCl4 (except Ge(BT)2Cl4), have been synthesised and characterized by elemental analysis, conductance measurements and I.R. spectroscopy. All the complexes have a 1:2 (M:L) stoichiometry and are non-ionic in acetone solution. Bismuthiol I has been found to coordinate through the exocyclic sulphur atom at position 2 or 5, whereas in the case of AT and AEB coordination occurs through the amino nitrogen. An octahedral trans configuration has been proposed for these adducts.

Kinetics and mechanism of substitution of cyanide ion in hexacyanoferrate(II) by EDTA catalysed by mercury(II) has been studied spectrophotometrically at 365 nm in potassium hydrogen phthalate buffer of pH = 5.0 and ionic strength, I = 0.1 M, maintained by (KNO3) at 25 °C. Effect of the pH and concentration of the EDTA, [Fe(CN)4-6] on the rate of reaction has been studied. The kinetics and mechanism of the reaction has been shown through dissociative mechanism. The mechanism of ligand substitution in the complex together with the kinetic data has been shown. The catalytic activity of mercury(II) has also been studied as a function of its concentration. The maximum reaction product was detected at pH = 5 after which a decline in absorption occurs followed by precipitation. It is an inexpensive method to identify and remove the cyanide ion in solution even in very low concentration of the order of 10-4 M.

Depending on the molar ratio, the potassium indolylboranates (III) are prepared from KBH4(I) and indole (II).

The title complex (I), prepared from the ligand and NiCl2in MeOH in 52% yield, crystallizes in P1.

The eight‐coordinate lanthanoid complexes (I) are prepared by 1:3 molar reaction of corresponding lanthanoid chlorides with the Schiff bases from sulfamethoxazole and salicylaldehyde or thiophene‐2‐aldehyde in ethanol.