Bis(μ2-4-amino-3-nitro­benzoato)bis­(4-amino-3-nitro­benzoato)octa­butyldi-μ3-oxido-tetra­tin(IV)

The tetranuclear molecules of the title compound, [Sn4(C4H9)8(C7H5N2O4)4O2], reside on a crystallographic inversion center. Both the two independent Sn atoms are five-coordinate, with distorted trigonal–bipyramidal geometries. One Sn atom is coordinated by two O atoms of the carboxyl­ate anions, one bridging O atom and two butyl groups and the other Sn atom is coordinated by an O atom of the carboxyl­ate anion, two bridging O atoms and two butyl groups. All the butyl groups are equatorial with respect to the SnO3 trigonal plane. The mol­ecular structure is stabilized by intra­molecular N—H⋯O hydrogen bonds. In the crystal, pairs of inter­molecular bifurcated acceptor N—H⋯O and C—H⋯O hydrogen bonds link the mol­ecules into chains along [10]. Weak inter­molecular C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.713 (2) Å] are also observed

(4-Chloro-3-nitro­benzoato)triphenyl­tin(IV)

In the title compound, [Sn(C6H5)3(C7H3ClNO4)], the four-coordinate SnIV atom exists in a distorted tetra­hedral geometry, formed by a monodentate carboxyl­ate group and three phenyl rings. The conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(5) ring. The aromatic ring of the 4-chloro-3-nitro­benzoate ligand makes dihedral angles of 75.64 (12), 64.37 (12) and 2.97 (12)° with the three phenyl ligands. The O atoms of the nitro group are disordered over two sets of sites in a 0.817 (5):0.183 (5) ratio. In the crystal, mol­ecules are linked via inter­molecular C—H⋯O hydrogen bonds into chains running parallel to [010]

Bis(μ2-2-amino-5-nitro­benzoato)bis­(2-amino-5-nitro­benzoato)octa­butyldi-μ3-oxido-tetra­tin(IV)

In the title complex, [Sn4(C4H9)8(C7H5N2O4)4O2], all four SnIV atoms are five-coordinated with distorted trigonal–bipyramidal SnC2O3 geometries. Two SnIV atoms are coordin­ated by two butyl groups, one benzoate O atom and two bridging O atoms, whereas the other two SnIV atoms are coordinated by two butyl groups, two benzoate O atoms and a bridging O atom. All the butyl groups are equatorial with respect to the SnO3 trigonal plane. In the crystal, mol­ecules are linked into a two-dimensional layer parallel to the ab plane by inter­molecular N—H⋯O and C—H⋯O hydrogen bonds and further stabilized by a π–π inter­action [centroid–centroid distance = 3.6489 (11) Å]. Intra­molecular N—H⋯O and C—H⋯O hydrogen bonds stabilize the mol­ecular structure. Two of the butyl groups are each disordered over two sets of sites with site-occupancy ratios of 0.510 (4):0.490 (4) and 0.860 (5):0.140 (5)

(2-Chloro-4-nitro­benzoato)(methanol)triphenyl­tin(IV)

In the title complex, [Sn(C6H5)3(C7H3ClNO4)(CH4O)], the five-coordinate SnIV atom exists in a trigonal–bipyramidal environment, formed by a monodentate carboxyl­ate group, three phenyl rings and a methanol mol­ecule. The axial sites are occupied by the O atoms of the methanol mol­ecule and the carboxyl­ate group, while the equatorial plane is formed by the C atoms of three phenyl rings. The benzene ring of the 2-chloro-4-nitro­benzoate ligand makes dihedral angles of 66.18 (7), 74.71 (7) and 77.39 (7)° with respect to the three phenyl rings. In the crystal, the mol­ecules are linked via inter­molecular O—H⋯O and C—H⋯O hydrogen bonds into a column along the b axis

Octa­butylbis[μ2-4-(diethyl­amino)­benzoato-κ2 O:O′]bis­[4-(diethyl­amino)­benzoato-κO]di-μ3-oxido-tetra­tin(IV)

The asymmetric unit of the title complex, [Sn4(C4H9)8(C11H14NO2)4O2], consists of two crystallographically independent half-mol­ecules. The other halves are generated by crystallographic inversion centers. In each tetra­nuclear mol­ecule, both of the two independent Sn atoms are five-coordinated, with distorted trigonal–bipyramidal SnC2O3 geometries. One Sn atom is coordinated by two butyl groups, one O atom of the benzoate anion and two bridging O atoms, whereas the other Sn atom is coordinated by two butyl groups, two O atoms of the benzoate anions and a bridging O atom. All the butyl groups are equatorial with respect to the SnO3 trigonal plane. Weak intra­molecular C—H⋯O hydrogen bonds stabilize the mol­ecular structures. In one mol­ecule, two of the butyl groups and the bridging benzoate anion are each disordered over two positions

Octa­butyl­bis­(μ2-2-chloro-5-nitro­benzoato)bis­(2-chloro-5-nitro­benzoato)di-μ3-oxido-tetra­tin(IV)

The title complex, [Sn4(C4H9)8(C7H3ClNO4)4O2], is a cluster formed by a crystallographic inversion center around the central Sn2O2 ring. Both of the two independent Sn atoms are five-coordinated, with distorted trigonal–bipyramidal SnC2O3 geometries. One Sn atom is coordinated by two butyl groups, one O atom of the benzoate anion and two bridging O atoms, whereas the other Sn atom is coordinated by two butyl groups, two O atoms of the benzoate anions and a bridging O atom. The O atoms of the bridging benzoate anion are disordered over two sites with an occupancy ratio of 0.862 (12):0.138 (12). One of the butyl groups coordinated to the Sn2O2 ring is disordered over two sites with an occupancy ratio of 0.780 (8):0.220 (8), whereas both of the two butyl groups coordinated to the other Sn atom are disordered over two sites with occupancy ratios of 0.788 (5):0.212 (5) and 0.827 (10):0.173 (10). All the butyl groups are equatorial with respect to the SnO3 trigonal plane. In the crystal, complex mol­ecules are stacked down [010] with weak inter­molecular C—H⋯π inter­actions stabilizing the crystal structure

(2-Amino-3-nitro­benzoato-κO)triphenyl­tin(IV)

The asymmetric unit of the title compound, [Sn(C6H5)3(C7H5N2O4)], consists of two independent mol­ecules. In each mol­ecule, the four-coordinated SnIV atom exists in a distorted tetra­hedral geometry and two intra­molecular N—H⋯O hydrogen bonds with S(6) ring motifs are present. In one mol­ecule, the benzene ring of the 2-amino-3-nitro­benzoate ligand makes dihedral angles of 42.74 (11), 89.66 (13) and 53.04 (10)° with the three phenyl rings. The corresponding dihedral angles for the other mol­ecule are 6.29 (11), 66.55 (11) and 62.33 (10)°. In the crystal, a weak inter­molecular C—H⋯π inter­action and a π–π stacking inter­action with a centroid–centroid distance of 3.5877 (12) Å are observed

2-Amino-3-nitro­benzoic acid

The title compound, C7H6N2O4, is approximately planar (r.m.s. deviation = 0.026 Å for the 13 non-H atoms). The mol­ecular structure is stabilized by intra­molecular N—H⋯O hydrogen bonds, which generate S(6) ring motifs. In the crystal, mol­ecules are linked via inter­molecular N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds into a three-dimensional network

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely